Can an Android app get data and interact with other apps that are currently running?

Question

I noticed that several apps like Facebook Messenger and LastPass can show widgets over other apps and even detect elements in those apps and fill input fields. I wonder how this is implemented and what are the limitations.

I'd really appreciate any references you could provide.

I'm new to Android development so please feel free to edit the question if it makes it clearer.

Answer 1

You can use a Content Provider.