From a formal taxonomic perspective, the African killies break down this way, per Huber:

Killifish, the common name for oviparous cyprinodontiformes fishes, are currently classified into 10 families (Huber, 2005 : full details HERE):

Aplocheilidae, only from India and Madagascar;

Nothobranchiinae from Africa but Madagascar with 2 subfamilies: Nothobranchiinae and Epiplateinae;

Rivulidae from Central and South America with 3 subfamilies: Rivulinae, Cynolebiinae and Kryptolebiinae;

Fundulidae;

Profundulidae, monotypic (which may be included also in Fundulidae as a subfamily or in Goodeidae as a subfamily, depending on authors);

Goodeidae, with 2 subfamilies: Empetrichthyinae, oviparous and Goodeinae, viviparous;

Valenciidae, also monotypic (which may be included also in Fundulidae as a subfamily, depending on authors);

Cyprinodontidae, with 2 subfamilies: Cubanichthyinae and Cyprinodontinae (with the latter in 3 tribes, Aphaniini, Cyprinodontini and Orestiadini);

Anablepsidae, with 3 subfamilies: Anablepsinae, viviparous, the monotypic Oxyzygonectinae, oviparous, and Jenynsiinae, viviparous;

Poeciliidae, with 2 subfamilies: Poeciliinae viviparous (except the monotypic subtribe Tomeurina -or tribe as Tomeurini, depending on authors-, oviparous) and Aplocheilichthyinae oviparous (in 3 tribes, Aplocheilichthyini and Procatopodini in the Old World and the monotypic Fluviphylacini in the New World). These 10 families are also accepted in international data bases on all fishes, such as Eschmeyer's Catalog and Fishbase, to ensure coherence and universality. The lower levels depend more on authors : a consensus view is selected herein.