Looks to me like Krobia xinguensis, aka Orange Spot Acara. Not as elongate as others in the genus, and the placement of the orange color is fairly distinct. Doesn't get too big either, similar size to Blue Acaras. This species has gotten to be somewhat available due to the ease with which they can be bred, and the fact that it's got some color.
C-F lacks a profile on this species. I would be happy to provide some photos if the moderator or admin wants to make one.