I simply want to take a installed app that I have no source code for. I want to make a new app that overwrites a button over the screen of the installed app. But, they run independently. New app only responds to simple button press and runs asynchronously

Does this mean you've abandoned your other thread?

I want to write an app that invokes a installed app I have to source code for. I want the installed app to be restricted to 3/4 of the screen and new app uses remaining 1/4. I want then to be asynchronous processe s running independently. Is this possibl

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>I want to make a new app that. It invode installed app and overwrites a button over the screen of the installed app... without communication with installed app,

Why do you want to make an app that blocks an app you don't have the source code for, and won't be communicating with?