I've got a couple in my ten gallon with a Betta. The Betta was very curious about them for a few days when they first went in the tank, because he had been living alone for about a month. He would notice them moving, and swim top speed across the tank to them and flare... but he never showed any actual aggression when I was watching the tank, and he doesn't even pay any attention to them now (2 weeks later)
I'm not really sure if the frogs I have are male or female, but they never really hang out with each other at all, and definitely don't fight.
I've already got them taking food from my hand, and they are now actually starting to come to the glass when I hover around the tank.
I bought some of the frog/tadpole pellets, and they will not touch them at all. They love freeze-dried bloodworms and tubifex, though!