You can also go through the Dark Mine to find gems, sometimes bits and sometimes ingots ((premium currency)). We just had a fun Halloween time with some special events and you can go around finding items called Exploring ((so just taking care of your horses via their pages, clicking around on tabs, looking through other players' horses etc, you can 'find' items that you can pick up to keep for yourself and or sell later on)). You don't have to be fully restricted to entering your horses into competitions, you can enter them into careers and or halter shows ((foals and adults)) and I believe I do own some horses that have never been shown and were career/halter horses before I shuffled them into showing.
I would also recommend Horse Fable, it used to be known as Eqcetera for a long while before becoming Horse Fable and I do enjoy it.