Thanks to the community I could solve my last problem. This --->(Google Maps API v2 - Fragment's error)
The app works on the emulator (it shows the "This app won't run unless you update Google Play Services), something normal, but when I put the .apk on the phone (4.2.2 version), it crashs!
I read somehting about different API keys. Now in my proyect, I have the API Key i got from the program (with the SHA1 fingerprint from Eclipse).
Do I need maybe a different one?
Thank you, and sorry for these two consecutive questions!