Egg NS is an Android-based emulator that claims to run games on mobile devices. On Android, it gained notoriety because:
The "exclusivity" of the file was the talk of the community. It wasn't on GitHub. It wasn't open source. The developers were anonymous, believed to be a splinter group of former Skyline contributors who had grown frustrated with the open politics of Android development and decided to target the most locked-down platform on earth as a challenge.
Once the app is installed, you will need to set up the required "SwitchDroid" folder structure on your device, place your game ROMs (in .XCI or .NSP format) into the appropriate game subfolder, and configure the emulator to locate the necessary key files and fonts. This process requires a certain level of technical expertise.