According to toucharcade there's an update coming this week to the iOS game Pocket Frogs by nimblebit.
It's been over a year since the last update, so you'd be forgiven if you've forgotten about this game. One person that hasn't forgotten about it is my 9 year old daughter, who still plays and maintains her frog habitats regularly.
One thing about this update is that they will be dropping the Plus+ network from the game in favour of standardizing around GameCenter, so in order to ensure you maintain your game save data, you need to make sure that you have the game installed right now, before the update! This allows your save data to be updated on the Plus+ servers, so that when the update hits later this week, it will transition to GameCenter smoothly.
If you've uninstalled the game, and you don't install the old version right now, your Plus+ game save data will not transition over.