Like you said not a large tank, but for $20 can you really complain? lol.
I personnally would add a nice piece of wood maybe a little rockwork, some nice plants and a small group of tetra, maybe some rummy nose or lemmon tetra. Pr glowlight danios even?
once i get it more established i will be moving a good deal of slate caves and some driftwood for the height factor. Right now im testing a variety of plants because my firemouth hates most, and seems to have fun ripping them to shreds.
I have 20 rummy nose that will be going in there and i just bought two giant danios earlier today for a little cycling, haha.