My high school aged son is doing some android app programming. He has an early version android phone (1.?) to test his programs, which doesn't seem to be working very well. I'm getting him a Nook Tablet (refurb) as a gift for testing but was also considering a cheap (used) phone as well. I can get an inexpensive Android 2.2 phone but I'm not sure if this is adequate. Any advice. Is it a good idea to have both platforms to test? The kid is really enjoying the process. I sure would like to encourage him... in a thrifty manner!

I appreciate any advice.