I always love making minimalistic demos because then you can see all the essential parts. I put together this short video with Delphi 10 Seattle to show the minimal parts necessary for to create an Android service. It is so simple. The Seattle release supports 4 different types of Android services. One thing this demo does show that is optional, is it create a sticky service that will relaunch if pushed out of memory. It doesn’t show how to talk to methods on the service – there are a few ways, which I can cover later. [Source]
BTW, Delphi 10 Seattle added support for iOS background execution too.