I made a game, and i have made a few developer products and some game passes. I'd like to know how i can make a gui appear only when they buy the product. If they cancel, it wouldn't appear.
When you process the user's receipt, you should fire a RemoteEvent that makes the GUI visible (or enable it, it doesn't matter.)
http://wiki.roblox.com/index.php?title=Remote_Events_and_Functions