Here are a couple of free apps worth noting:
Toca Kitchen Monsters: This app just launched today so they may raise the price at a later date. My kids really enjoy all the apps by this developer.
Toddler’s Seek & Find – My Little Town (HD+): An interactive picture book. We just downloaded it so I can’t vouch for it yet because my little one hasn’t played with it. Still it’s free and you can always delete it later.