Story Bots is a great iPad app for little people. The free version gives you three songs to play. Songs include Mary Had a Little Lamb, Row Your Boat and This Old Man. If you upgrade the app is based on a membership of $4.99 per month for 11 songs (personally I think this is very expensive) however the free version is great fun!
I found another two iPad apps called Alien Buddies which costs $1.99 and Cutie Monsters which costs $2.99. I managed to get these apps for free by checking my Apps Gone Free app on a regular basis. Remember, Apps Gone Free is free and it provides you with notifications of apps which are currently going for free. I have embedded a video demonstration of Alien Buddies and Cutie Monsters so you can view the app before deciding to buy them. None of the apps are available in Google Play, however, if you enter the names of the apps there are a few good look apps that are free which you may like to try.