First, welcome to Tropical Fish Keeping forum.
As you currently have livebearers, if there is male/female you will soon have many, many more.
Aside from the above, a 10g is not a lot of room, so a substrate fish would work and provide some different interest. A trio of one of the medium-sized Corydoras species (should be no less than 3 corys, they are shoaling fish and live in groups) would work, or perhaps a small species of catfish like a Whiptail Catfish.
We have fish profiles, second tab from the left in the blue bar across the top; when a fish name is shaded in a post it means there is a profile, you can click on the shaded name to see it.