Nintendo Switch owners can make their console run homebrew and one of the perks is that it is possible to install Android on it. Linux and Windows have also been tested on the homebrew Switch.
Since Nintendo Switch uses a custom variant of the Nvidia Tegra console architecture, it has already support for Android. Nvidia uses this architecture in their Shield device which can stream or play Android games.
Someone has now created an unofficial custom ROM for the Nintendo Switch hardware. As always, we recommend to just use it for testing purpose as there is always security or hardware risk with such modifications.
LineageOS 15.1 for Nintendo Switch by switchroot. This is the first publicly available Android ROM for the Nintendo Switch. Based on the Nvidia Shield TV builds it brings a smooth and powerful Android experience to your Switch in both handheld and docked mode.
As for the purpose of this ROM, it is just a proof of concept and while you will be able to use some apps, it is very likely that not everything will work as intended.