As an experienced Analyst / Programmer (25+ years as a professional) I am new to MIT App Inventor. My first impressions: Fantastic. I have used many IDE's and Compilers from C/C++ through C# and Delphi (for the Americans who have never been to Greece where the name originated, it is correctly pronounced as Del.fee) and although the App Inventor system is blocky, it is very intuitive.
My first project is a BLE app to control an Arduino board (STM32WB5MM-BK) which controls the opening and closing of a sliding gate. I wrote the first app using Android Studio (using an example app found on the web) which I hated although did get it working with great pain and a lot of time. Producing the equivalent in App Inventor took less than a week of part time work and is far more stable and works with the latest version of Android.
I am putting the whole system together in a magazine article which I hope to get published soon, at that point I will make available all details on my Github page.
Thanks MIT
Denny Wells