This refers to unofficial fighting games for the Android operating system. These games are typically created using the M.U.G.E.N. engine and feature characters and elements inspired by the “Jump Force” video game and various anime and manga series published in Weekly Shonen Jump. These are not officially sanctioned products.
The appeal stems from offering a readily accessible, portable fighting game experience on mobile devices, often with a massive roster of characters from different popular franchises. Their development fills a niche for fighting game enthusiasts and fans of anime/manga who desire a crossover experience. However, due to their unofficial nature, they often lack the polish and legal backing of commercial games.