K.A.
I've had an iphone fora while and just got an ipad for my birthday.We just went app happy when we got the ipad LOL
I don't know the ages of your kids. I've got 9,6 & 17 months so I have a range of things.
Some fun ones that we have are
Tesla Toy (free)
Pocket Piano (free I think)
Disney's Fairies Fly (does cost but it the Most played with game between all of us)
The Wiggles have 2 read along books (cost is minimal)
Of course I have Facebook that I use all the time
I have a great app for sign language "baby signs" because we use signs with our kids. It's a good one.
We have a whole bunch of Disney apps. They do a good job at the ones they put out. Those all get played a lot.
There are so many good things available :)