Internet Browser (unconfirmed) is a web browser preloaded on the Nintendo Switch. It is presumably based on Webkit.
(Its unknown if the ns next-to-1.0 have a "web browser", but is confirmed? that the ns (next-to-1.0) have a browser applet to hotspots that need authentication)

Known User Agent Strings

System Software Release Date UA String
Unknown Unknown Mozilla/5.0 (Nintendo Switch; WebApplet) AppleWebKit/601.6 (KHTML, like Gecko) NF/4.0.0.4.19 NintendoBrowser/5.1.0.11386

Referred to this?