Imagine Champion Rider
I completely adore this game. It lets you pick your horse's breed, color, personality, and loads more. I have a lovely horse and you can buy all the gear and tack for your horse, go on peaceful rides, go to lessons, talk to friends, learn about horses by collecting horse cards on rides. It's a fab game and it is neighing with fun.
I would advise you to buy it if you like horses because it is all horse fun!