It's probably a Rubricatochromis species. Until a recent revision, they were in Hemichromis. They're a western/Central African family of very similar, aggressive members of the Cichlid family. In the aquarium, both groups are called Jewel Cichlids.
Flagfish, Jordanella floridae, are killifish, related to the pupfish group. They really resemble Cichlids, and over the years, a lot of people going to pet stores have thought they were Cichlids. It's something called convergent evolution, where completely unrelated species can have very similar body shapes or colours, because what works in nature tends to show up again and again.
The screenshot is kind of grainy, and it could almost be an Anomalochromis too. They are a small Northwest African group related to the jewels, but far more peaceful.