Earlier this year, Citra, the 3DS emulator, was officially released for Android devices. If you thought that this was the biggest emulator news for Android this year, then you thought wrong. Enter Egg NS: a working Nintendo Switch emulator for Android.
While it was made publicly available a few days ago, Egg NS was developed over a period of two years by the NXTeam Studios according to the official website. The website also claims that the team is based in the U.S. but that remains to be confirmed especially considering the typos and Chinese texts on the website. The video above is one of the few that are available at the time of writing and have been posted on the official website but GBAtemp member @mattyxarope noted that YouTuber Taki Udon confirmed the existence of Egg NS on Discord (under #android-devices) and shared additional videos (some of which you can see here, here and here). Another YouTuber, ETA Prime, also said that it's a "a legit Switch emulator for Android" and shared a picture of the emulator running Hollow Knight with a video planned for a later release.
GBAtemp member @bylaws who worked on getting Android to run on the Switch noted that Egg NS "uses stolen code from yuzu for the GPU emulation".
According to the official website, Egg NS works on Snapdragon 855, 855+ and 865 phones, with a list of compatible phones available on their website. The catch is that the emulator works specifically with the $100 GameSir X2 controller which is available for preorder, since it apparently provides a code required to run the app. Upon closer look, the Egg NS logo bears some similarity to GameSir's Happy Chick app (the chick inside a cracked egg) which itself runs a number of emulators.
NXTeam Studios has also shared a games compatibility list, detailing the performance of each game they tested. Understandably, less graphically-demanding games like Cuphead and Enter The Gungeon seem to run better in Egg NS, with the exception of Pokemon Sword & Shield which is said to have a "perfect" compatibility.
Given that Egg NS is an emulator, not all games will run as well as on the native console. You might be better off with a Switch for now but it does show the potential of mobile phones and with time, Egg NS might improve and similar emulators with better performance might even pop up.
@mathew77 already started a discussion thread linked as the source material below. As for Egg NS' website and download links, you can find it from the YouTube videos but aren't shared in this post as they contain links to illegally-shared files.