Is there a way to text back and forth with someone who has an android phone on the N7?
GChat? Are you looking for an AOL app? There's quite a few in the Play Store that should work just fine.
Do they need the app too, or just to their cell number ?
Going to need MS Messenger, AOL, Yahoo Messenger or Skype or ? You can use skype to make voice calls to cell and landline numbers for a price. Google it.
Or Skype can make video calls between skype users just with their skype user names.
Google voice let's you do that for free as long as you're in the US (and Canada iirc) and for a small fee to other countries. Skype charges for any call to cell or landline
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