However, although the app currently allows you to sign into your Nintendo account, doing so returns an error code, along with a message that the servers are currently undergoing maintenance.
We assume this message means that the servers aren't yet live, but that the app has been pre-released in advance of Splatoon 2's release on Friday.
The app does not yet appear to be available for Android devices.
The console's features on a phone
The app will likely prove to be an important element of the Switch's online service. You'll need to use this app to enable voice chat functionality in online games, and it will also be instrumental in partying up with friends for online gaming.
However other consoles have this functionality built into the console itself, leading to concerns that Nintendo is risking over-complicating its online functionality.
Past Nintendo consoles have had an equally difficult relationship with voice chat. Using voice chat on the Wii and Wii U relied on users entering lengthy friend codes in order to enable voice chat – a feature that has been de-prioritised on the Switch.
This has been a step taken in an attempt to protect children from inappropriate language used online. As a result, it's rare to find players using voice chat in online Nintendo games.
The Nintendo Switch app is a big change for Nintendo, but the company is still committed to doing things differently to its competitors.