Your messaging isn't clear to me. I have read both:

"Notify friends with your game plans and keep up with theirs."

and

"GameCall makes it simple to notify your friends with your game plans, and keep up with theirs."

Neither of those make it clear to me what your app does exactly. When you talk about games, are you talking about sport? Game is pretty generic. I would try to simplify the messaging and make it as clear as possible.

The actual app looks nice from the screenshots.