Doesn't have a shell? The pic isn't very good so it's hard to tell.
Could be:
Stomatella - will have a tiny flatish shell that looks like a finger nail.
Collinista - round shell like a turbo that is white and brown pattern
Dibs turbo - same round shell but the shell is mixed with colors of green, blue, sometimes pink.
All are good algae eaters and not a problem in the system. Congrats!
Get a better pic if you can't ID it from here.