If you have all apple devices, just link the new tablets to your itunes account. The boys' ipads are both on my account. When we get a new game, it shows up on all three ipads. If it's not appropriate for one of them (too easy, too hard, etc..) , I manually delete it from his ipad screen. But it's always there in my itunes account if I want to add it again.
What she said...we always know when someone buys a new app or gets a free one because we all get it. We are all under one iTunes account. Then like she said if we like it we keep it if not we delete it.