Android version who have acces to the aplication?

When i create the application, i remember that i put the disponibility to the maximum. But somebody just told me he don't have acces to it with his old android phone. 
Where and how i can check and change the version of android who can have access? The application doesn't need a lot of graphisme.



According to the MIT technical team App Inventor supports a minimum version of Android 1.5 (Cupcake), SDK Level 3. Applications built with App Inventor will run of on any Android device that is running Android version 1.5 (Cupcake) and up. (  https://groups.google.com/forum/#!searchin/mitappinventortest/minimum$20$20Android$20version/mitappinventortest/_JRGnwcrDs8/IKLitLziit4J   )

App Inventor 2 will be upgraded to use Android API 4 (from the current 3) in the very near future to support Tablets and high end devices   Once the upgrade happens, the lowest supported version of Android might be 2.3  (I do not know for sure...sorry).

API Level 4 is Android Version 1.6, also called Donut

see here https://source.android.com/source/build-numbers.html

which means, after the tablet release, the minimum version will be Android 1.6

Thanks,

Like the application have been made by mit app inventor 2, the minimum system to get accees is android 1.6.

currently it's Android 1.5 and after the tablet version release it will be Android 1.6