I second on the skinned peas, and also Aquarian pellets. If I'm feeling rich/the LFS has a sale I get live brine shrimp or bloodworms, and they always get a portion of frozen bloodworms when I feed my African Dwarf Frogs because the cube is too big for my frogs. I also make sure they've got some cheap plants in there that they munch on between feedings - it's annoying to clear up the bits and replace the plants but it makes me feel a bit like they are living a bit more naturally than just a glass tank. I use anarchis (elodia densa, also known as oxygenating weed where I am).