App Inventor Extensions

Alarm Manager Extension
with Notification or Autostart

See the App Inventor Extensions document about how to use an App Inventor Extension.

For questions about this extension or bug reports please start a new thread in the App Inventor community. Thank you.

For feature requests please contact me by email. To be a sponsor of a new method already is possible starting from only 10 USD! With your contribution you will help the complete App Inventor community. Thank you.

• History (Previous Release Notes)

  Oct 30th, 2020: Version 1: initial version for App Inventor. This extension does not work in Kodular, because Kodular still does not support AndroidX libraries.

  Nov 3rd, 2020: Version 2: bugfixes, alarms now will be reinitialized after rebooting the device, new methods GetAlarms, OpenNotificationSettings, intensive tests using devices starting rom Android 5 up to Android 11, Thank you Anke!

  Nov 19rd, 2020: Version 3: new features repeat weekly, monthly, yearly added. AfterAlarm event added. Bugfix updating or cancelling an alarm. Now after an alarm (interval type ONCE) has been triggered it will be removed from database.Thank you Per por being the sponsor of version 3!

  Nov 22th, 2020: Version 4: "bells and whistles" version: properties small icon, large icon, big picture, big text and color added

  Jan 9th, 2021: Version 4a: bugfix registerForOnResume and registerForOnStop added

  Jan 20th, 2021: Version 4b: minor improvement for multiple screen apps and the AfterAlarm event. For multiple screen apps the AfterAlarm Event will fire only for those screens, the extension is being used or has been dragged to the working area.

  Feb 11th, 2021: Version 4c: BootService fixed for the 5 optional values (smallIcon, largeIcon, largeText, bigPicture, color), GetAllAlarms fixed. In case you are already have been using Version 4b in production and you still get an error after using GetAllAlarms in version 4c then please contact me by email. Thank you.

  Oct 1st, 2021: Version 5: Autostart property added including the methods HasAppearOnTopPermission and OpenAppearOnTopSettings. Thank you Henry for being the sponsor of version 5!

  Dec 28th, 2021: Version 5a: bug fix for Kodular: class name issue to start app after notification click

  Aug 16th, 2022: Version 5b: SDK31 update(1): exported = "true" added in manifest for broadcast receivers

  Sep 26th, 2022: Version 5c: SDK31 update(2): pending intent FLAG_IMMUTABLE, permission SCHEDULE_EXACT_ALARM added

  Oct 21th, 2022: Version 5d: SDK31 update(3): pending intent FLAG_IMMUTABLE for BootService added

  Nov 10th, 2022: Version 6: new method StartAtBoot to trigger a notification or autostart the app at boot time

  May 10th, 2023: Version 7: SDK33 update: HasPostNotificationsPermission method added, permission android.permission.POST_NOTIFICATIONS added in Manifest

  Sep 26th, 2023: Version 7a: Extension rebuilt to avoid "ERROR: DX returned an error code" for projects, having 2 extensions or more which use proguard to obfuscate their code, see also Pull request 3004.

  Jan 6th, 2024: Version 7b: "set exact" alarm replaced by "set" alarm because of Android 14 behavioral changes. The extension now does not use SetExact anymore, because Applications are strongly discouraged from using exact alarms unnecessarily as they reduce the OS's ability to minimize battery use. Also the itoox-wrapper library has now been added directly into the alarmmanager extension to avoid build conflicts with other extensions, which also use the itoox-wrapper library.

  Jan 27th, 2024: Version 8: itoo integration: Now we can execute almost any logic in the background (no user interface components) after an alarm occurred and even define new alarms in the background. Please be aware, that there is no user interface available in the background. Thank you Kumaraswamy for this amazing framework! Further minor features: send always local broadcast, helper blocks added for StartInterval and StartRepeatingInterval, AskForPostNotificationsPermission method added to replace the OpenNotificationSettings method.

  Mar 4th, 2024: Version 8a: bugfix to save new alarm if alarm time already passed for autostart = true.

  Apr 6th, 2024: Version 9: you now can define a custom notification sound for your app, you can choose to schedule exact or inexact alarms, the notification now can be configured to have one or two buttons and you can define some functionality to get triggered without opening the app (using the OnReceiveButtonClick event handler).

  May 14th, 2024: Version 9a: setExact replaced by setExactAndAllowWhileIdle.

• Latest releases - release notes

  July 25th, 2024: Version 10: SDK 34 update. The extension can now additionally be used to start your app at the given time above the lock screen in case the device is locked. Parameter autostart has been replaced by startMode, new methods HasFullScreenIntentPermission, AskForFullScreenIntentPermission added (available starting from SDK 34), notification click starts Screen1 if Lockscreen is not available

  Jan 17th, 2025: Version 10a: Fix for Niotron and Kodular to start the app after notification click also when another package name is used. Additionally to avoid new Google restrictions ( for details see below Q8 in the Q&A section) I now additionally provide a LITE version of the extension for those who only like to use StartMode = Only Notification

  Feb 5th, 2025: Version 10b: Fix for Niotron and Kodular to open app always on Screen1 after Notification click (except LockScreen).

  Mar 7th, 2025: Version 11 (currently in BETA): new start mode 'Only Background processing" added to do some background processing at a given time without showing a notification.

Description

Alarm Manager Extension to send a notification or autostart the app at a given time even above the lockscreen or at boot time only once or repeated by an interval. You can define a start text, which will be passed to your app in method 'get plain start text' and trigger some action after your app is started. Also of course works if your app is not running. The defined alarms will be reinitialized after rebooting the device. You also can define several alarms, just use a different id for each alarm. Starting from version 8 you can execute almost any logic in the background (no user interface components) after an alarm occurred and even define new alarms in the background, Please be aware, that there is no user interface available in the background.
Minimum API level is 21 (Android 5).

Required permissions:
android.permission.RECEIVE_BOOT_COMPLETED, android.permission.FOREGROUND_SERVICE,
android.permission.SYSTEM_ALERT_WINDOW (added in version 5 to open apps above other apps), android.permission.POST_NOTIFICATIONS (added in version 7 to be able to receive notifications for newer devices), android.permission.SCHEDULE_EXACT_ALARM (you can decide if you want to use exact alarms or not), android.permission.DISABLE_KEYGUARD, android.permission.WAKE_LOCK, android.permission.USE_FULL_SCREEN_INTENT (addeed in version 10 to be able to open app above the lockscreen)

Kodular Restrictions

• The block get plain start text can't be used, see also this Kodular error report as of Sept 30th 2021 Yes, the error has been reported more than 2 years ago and up to now they did not fix it. Also there are countless errors more in their system. Kodular is in the process of migrating into App Inventor. Decide yourself, if you like to use Kodular under these circumstances... See also my contribution here. It would be wise to start your project in App Inventor and avoid the migration chaos.
• I will provide support for the OnReceive event handler only in MIT App Inventor. This feature is not tested in Kodular. Use it in Kodular at your own risk.

Properties for functionality

Reference screen for Itoo where the procedure 'OnReceive' exists. If no property is set, the extension will take "Screen1" as the reference by default.

OnReceive has the arguments title, text and startText.

Note: The OnReceive event handler also will be called if the app is in the foreground!

DEPRECATED. Property autostart has been replaced by property startmode. Autostart = false has been migrated to startMode = 1 (Only notification) and autostart = true to startmode = 3 (Start Always).

StartMode for alarm time.
Possible values are: 1, 2, 3 or 4. (1 = Only notification, 2 = Start Above Lock Screen or Notification, 3 = Start Always, 4 = Only Background Processing).
Default value is 2.

1. Only Notification
   Display a notification. After clicking the notification, the app will be started and screen "LockScreen" will be opened. In case that screen does not exist, Screen1 will be opened.
2. Start Above Lock Screen or Notification
   If the device is locked, the screen called "LockScreen" of the app will be opened above the lockscreen of the device! After closing the app, the device still will be locked. If the device is unlocked, display a notification. After clicking the notification, the app will be started and screen "LockScreen" will be opened. This is the recommended start mode to not disturb the user while using other apps, see also here. Make sure to have a screen called "LockScreen" in your app. It is not possible to open another screen above the lockscreen.
3. Start Always
   The app will always start and open the screen called "LockScreen" no matter the state of the device. This might be annoying if the user is in a phone call or using another app. For this mode, additionally the permission "Appear On Top" is required. Make sure to have a screen called "LockScreen" in your app. It is not possible to open another screen above the lockscreen.
4. Only Backgrouund Processing
   Do some background processing at a given time without showing a notification.

Note: For option 1 (Only notification): For newer Android versions you need Post Notifications permission. See methods HasPostNotificationsPermission and AskForPostNotificationsPermission.

Note: For options 2 (Start Above Lock Screen or Notification) or 3 (Start Always): Displaying an app above the lockscreen (also known as full screen intent) requires for Android 14+ devices additionally full screen intent permission. After each app update this permission needs to be refreshed again! Its use is restricted: For apps targeting Android 14 (API level 34) or higher, apps that are allowed to use this permission are limited to those that provide calling and alarms only. You can use method HasFullScreenIntentPermission to check if your app has the permission; if not or if your app has not been approved for default enabling use of full screen intents you can use method AskForFullScreenIntentPermission to launch the settings page where users can grant the permission.

Note: For option 3 (Start Always): additionally the user needs to grant "Appear On Top" permission. See methods HasAppearOnTopPermission and OpenAppearOnTopSettings. So while the user is using another app, at a given time your app will get priority and will appear on top of the other currently running app.

Note: For option 4 (Only Background Processing): no permission is necessary. You can think about asking for ScheduleExactAlarm permission in case this is required for your use case.

Note: To be able to autostart the app at a given time make sure to close the app using the close application block, else the app will not start, because it is already running.

Note: Use the new feature to open the app above the lockscreen for new apps only, because the notification channel needed an update to be able to use full screen intents.

Returns/Specifies whether app should schedule exact alarms. Default value is False.

Note: Google recommends to use exact alarms wisely to reduce battery consumption. See also Use cases that might not require exact alarms. If you decide to use exact alarms, then the user needs to grant the SCHEDULE_EXACT_ALARM permission, see method AskForScheduleExactAlarmPermission below.

Properties for Notification style

Returns SmallIcon for notification. Recommended size is 96x96.

Sets SmallIcon for notification. Recommended size is 96x96.
Note: this feature is available starting rom Android 6 (API Level 23). For older devices this setting will be ignored. The small icon must be in png format and have a transparent background.

Returns LargeIcon for notification. Recommended size is 256x256.

Sets LargeIcon for notification. Recommended size is 256x256.
Note: this feature is available starting rom Android 6 (API Level 23). For older devices the application icon will be used as large icon.

Returns BigText for notification

Sets BigText for notification
Note: you can only use bigPicture or bigText. If you specify both, then only bigText will be displayed.

Returns BigPicture for notification. Minimum: 512x256, Balanced: 1024x512, Maximum: 2048x1024.

Sets BigPicture for notification. Minimum: 512x256, Balanced: 1024x512, Maximum: 2048x1024.
Note: you can only use bigPicture or bigText. If you specify both, then only bigText will be displayed.

Returns the notification color, i.e. the color as an alpha-red-green-blue integer.

Specifies the notification color. Note: you can use any integer color code or the color blocks of App Inventor. In the example alarmmanager app I used a simplified version of Italo's color picker example, see also the example project "StatusBarColor blocks" in the tools extension documentation.

Returns/Specifies the custom Notification sound file stored in the assets of the app. The sound file will be copied into the /Ringtones folder of your device and used from there.
Note: if you want to use a custom notification sound file for your app, you have to set it before using the Start or StartRepeated method. The extension uses only one notification channel to keep the extension as simple as possible. The sound file later can't be changed anymore, because this is set in the notification channel directly.
Note: this feature is available starting from Android 8 (API Level 26). For older devices this setting will be ignored.

Button1Text for notification
You can define the text of button1, which will be displayed in the notification and configure the event handler OnReceiveButtonClick to trigger some functionality after the button has been clicked without opening the app.

Button2Text for notification
You can define the text of another button2, which will be displayed in the notification and configure the event handler OnReceiveButtonClick to trigger some functionality after the button has been clicked without opening the app.

Screenshots

Note: These are screenshots taken from a Samsung Galaxy A51 device running Android 10. Depending on the Android version you will get slightly other results.

Methods for Permissions

Returns true, if app is able to schedule exact alarms.
Note: Apps can schedule exact alarms only if they have SCHEDULE_EXACT_ALARM permission or they are on the device's power-save exemption list.

Ask for Schedule Exact Alarm permission. Required starting from SDK 33 to schedule exact alarms.

Returns true, if post notifications permission has been granted, else false. This permission is available starting from SDK 33.

Ask for Post Notifications permission. Required starting from SDK 33.

Returns true, if app has full screen intent permission, else false. This method is available starting from SDK 34.

Ask for Full Screen Intent permission. Required starting from SDK 34 for apps that did not complete the Google Play declaration or have not been approved for default enabling use of full screen intents. This method is available starting from SDK 34.

Open Notification Settings (deprecated).
In version 8 method AskForNotificationsPermission has been added. You might want to use the new nethod instead of OpenNotificationsSettings.

If user likes to autostart the app, special permission is required, Using this method, you can check, if the permission has been granted.

Open Appear On Top Settings to enable Autostart for app.

Methods for functionality

This method is for alarms which only should fire once, but starting from Version 3 also for long term intervals. Start an alarm at a given date/time (instant). In case the time already has passed, the alarm will start asap. Define the title, text and start text of the notification. Interval can be one of the following values: 'ONCE', 'WEEK', 'MONTH', 'YEAR'. The start text is the value which will be passed to your app in method 'get plain start text'. Use your own id (integer value). If you use the same id again, then the previously defined alarm, which already uses that id will be overwritten..

Note: Starting from Version 9 you can choose if you want to set exact or inexact alarms. Set property ScheduleExactAlarms accordingly.

Note: You might want to check, if your app has post notifications permission using the new method HasPostNotificationsPermission.

Note: You will have to build the app to be able to test this method.

Start a repeating alarm at a given hour and minute (short term intervals). Define the title, text and start text of the notification. Interval can be one of the following values: 'FIFTEEN_MINUTES', 'HALF_HOUR', 'HOUR', 'HALF_DAY', 'DAY' The start text is the value which will be passed to your app in parameter 'get plain start text'. Use your own id (integer value). If you use the same id again, then the previously defined alarm, which already uses that id will be overwritten.

Note: Starting from Version 9 you can choose if you want to set exact or inexact alarms. Set property ScheduleExactAlarms accordingly.

Note: You might want to check, if your app has post notifications permission using the new method HasPostNotificationsPermission.

Note: You will have to build the app to be able to test this method.

Start an alarm at boot time.
The start text is the value which will be passed to your app in method 'get plain start text'. Use your own id (integer value). If you use the same id again, then the previously defined alarm, which already uses that id will be overwritten."

Note: You will have to build the app to be able to test this method.

Return a list of all alarm Ids.

Retrieve the alarm in JSON format stored under the given id. If there's no such id, then return empty string.

Get all Alarms in JSON format.

Cancel an alarm using the id you previously used to start the alarm.

Events

Event returning success or failure after starting an alarm.

Event returning success or failure after canceling an alarm.

Event indicating that an alarm occurred. Event will fire only if the app is up and running, else depending on the startMode a notification will be displayed or the app will open screen LockScreen. For multiple screen apps this happens only for those screens, the extension is being used or has been dragged to the working area.

Example App "Simple Notification" to get a daily notification at 9am

The example uses inexact alarm times. Google recommends to use exact alarms wisely to reduce battery consumption. To set exact alarm times see property ScheduleExactAlarm.

Screenshots:

Example App "Alarm Manager with Notification Test"

Screenshots:

Example App "Lockscreen"

This is a a test app to demonstrate the open above lockscreen feature of the alarmmanager extension.
Instructions:
1) First grant the necessary permissions. After that, the Start button will appear.
2) Click "Start".
3) Close the app and lock the device.
4) After 1 minute the app will start above the lockscreen and open screen "LockScreen".

Note; In the example app additionally I'm using the Ignore Battery Optimization extension.

Screenshots:

Test

Tested successfully on several devices starting from Android 5 up to Android 14.

Questions and Answers

Q1: Woud it be possible to add a feature to the extension to restart my app at a defined date and time in the future?
A: This is now possible starting with version 5. However Google restricts this feature like this (taken from here): Android 10 (API level 29) and higher place restrictions on when apps can start activities when the app is running in the background. These restrictions help minimize interruptions for the user and keep the user more in control of what's shown on their screen. In nearly all cases, apps that are in the background should display time-sensitive notifications to provide urgent information to the user instead of directly starting an activity.
Also starting from Android 10 the app must have been granted the SYSTEM_ALERT_WINDOW permission by the user to be able to restart itself from the background. And in Android 11 this has been even restricted further.
Starting with version 10 the extension is also able to start the app above the lockscreen in case the device is locked.

Q2: I'm using a Xiaomi device and the alarm does not work anymore after rebooting the device. What can I do?
A: After rebooting the device, the Boot Service must reconfigure the alarms. However on Xiaomi devices, Auto Start is disabled by default for all applications. See here how to enable it for your app. See also https://dontkillmyapp.com/xiaomi

Q3: How to get an instant of the 25th of the current month?
A: See my answer here.

Q4: How to initiate a specific screen after clicking on push notification?
A: You will have to use the Screen.Initialize event like this

   if not is empty get plain start text
   then open another screen "your screen name"

You can find the not block in the logic drawer, the is empty block in the text drawer and the get plain start text block in the controls drawer.

Q5: I am trying to send a text message using AfterAlarm method when app is on the forefront sms goes but it does not go when app is in the background or after phone restarts
A: This is now possible starting from Version 8 of the extension.

Q6: I would like to start my app regularly to do something without user interaction. Is this possible using this extension?
A: Yes you can. Starting from Version 10 of the extension it is possible to start your app above the lockscreen (in case the device is locked) or above other applications in case the device is in use. Also depending on the use case rather than starting the app what about executing some functionality in the background after an alarm occurred? See chapter itoo integration above.

Q7: Method StartAtBoot does not work for me. What I'm doing wrong?
A: Which device and Android version are you using for your tests? Xiaomi? Try to disable battery optimization, see also See also dontkillmyapp.com. For Redmi: App Settings - Battery Optimisations - Do not optimise battery. You may also do this App Settings - AutoStart - Enable Auto Start.

Q8: I'm using StartMode = Only Notification. After uploading my app to Google Play I get the following message displayed: Issue found: Permission use is not directly related to your app's core purpose. We found that your app is not compliant with how USE_FULL_SCREEN_INTENT permmission is allowed to be used. Specifically, the use of the permission is not directly related to the core purpose of the app.
A: To avoid this Google restriction I now additionally provide a LITE version of the extension for those who only like to use StartMode = Only Notification.

Test the functionality of the Alarm Manager with Notification extension

3 test apps are available in Google Play. You can test the extension following these steps

1. Follow the opt-in URL for the alarmmanager example app to get access to the app and to be able to download it to your device. Here you can test all the notification features.
2. Follow the opt-in URL for the Lockscreen example app to get access to the app and to be able to download it to your device.
3. Start testing.

Buy the Alarm Manager extension for App Inventor

You can buy this extension (aix file).
With your payment you accept the terms and conditions below.

Payment options

Then send me the transaction id by email and tell me the extension you are interested in.

After having received your payment I will be happy to send the download link to you. Please let me know your Google account! I usually will send the download link not later than 24 hours after having received your payment.
Thank you! Taifun

Terms and Conditions

• You are buying a digital product and agree to the No Return, No Refund Policy.
• You have tested the example app successfully on your device before buying the extension.
• You can use the extension in as many projects as you like and pass the generated apk files to as much end users as you like, also of course you can publish your apk files to Google Play and other services
• This is a single user license for you as App Inventor developer, which means, the extension (aix file) is only for you to use. You are not allowed to pass a paid extension (aix file) or a project (aia file) which contains a paid extension to someone else, to post it in one of the communities or to distribute it to others. In case you are interested in a multiple user license, please contact me by email.
• There are a lot of different Android devices available in the market. I'm not able to test the example on all these devices and therefore also can not guarantee, that the example is running on your device.
• THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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