The great thing about open source software is that anybody can use it. The not-so-great thing about open source software... is that anybody can use it. Such was the case with two N64 emulators battling it out on the Google Play Store. According to a massive Reddit thread, the original game emulator was called "Mupen64Plus Android Edition", developed by Paul Lamb
and based off of the open-source emulator Mupen64Plus. Under the General Public License, anyone can use the Mupen code for any project they like (including charging for it) as long as proper attribution is given. Paul put up his app on the Google Play Store, and for a while, all was right with the world.