Projdi si tohle:
Creating an Android service with Delphi:
http://blog.blong.com/2013/11/delphi-and-android-services.html
http://blog.blong.com/2013/11/delphi-and-android-services-part-2.html
And setting up your Android Manifest for an Android widget:
http://stackoverflow.com/questions/8426477/android-declare-widget-in-manifest