Pony Friends 2
Well... This game is excellent!
You get to do lots of things such as brush and give your pony a bath, go on a trail ride, enter a race, go show jumping, go see the vet, go to the pony market, go to pony club (at pony club you can go on quests, learn a trick and get some tips). You can also go to the shop, go to your house, go to the stables and visit the field, pet it, give it some food, check the pony diary and practice your tricks in the field.
There really are lots of things to do!