I taught my old Betta, Jim that (R.I.P.) and I just taught my new Betta, Otis that a few days ago, I love Bettas. Jim could go through my fingers when I made the "OK" sign, and he would jump through the feeder ring and out of it when I gestured a rainbow. Awesomely cool fish, I love 'em to death.
I trained my Betta "Fred" to swim through a hoop.
But unfortunately I had to put him (he had very bad injuries).