Just thought I would ask this question:
When I write an app with App Inventor 2, what versions of Android will it run on?
I ask because the other day I downloaded an app (not AI2) that didn't work on my phone (Android v5.1.1). I found out later that the app required Android v7.1.1 or above, despite the manufacturer of the app telling me it would work with ALL smartphones.
The reason for that is not as simple as you might imagine - to have certain high-tech features in an App, the Android version has to support them. App Inventor probably supports lower Android versions than most other platforms.
A brief explanation from MIT guru Evan Patton
That's a complicated question, but most features work as far back as Android 2.1 (SDK 7). Extension support is available starting at Android 2.2 (SDK 8). Firebase needs SDK 10 (Android 2.3.3). While not part of the core App Inventor, the BluetoothLE and related IOT extensions need Android 5 (SDK 21). All components are aware of the permissions model introduced in Android 6.0 (Marshmallow) and will ask for the appropriate permissions when running on that version or newer.