A friend of mine has asked me to translate a few phrases from English into Russian for a mobile app he's developing. Like many other mobile app developers, he wants to strike a friendly, informal tone with users, and I want this to be reflected in translation. So if I have phrases like "You've received a message from X," or "I've created this song for you," would вы come off as too formal, or is ты too informal? Just trying to get a better sense of this nuance within the context of mobile apps.
Thanks!