I have one question - I'm starting to learn android development and I want to know one thing - can I write app that will adapt to phone on which is installed? I mean - for example - app will use wifi, gps and ringtone to give me location of a phone. If phone has gps - it will use gps. If not - it will switch to wifi. If phone is old and has no wifi or gps it will ring. I want detect it automaticaly beacuse app will be installed on different models and by users that know nothing about device so it must be done inside of app and not by user.