July 21 was the date set for the Nintendo Switch Online service to go live, but it seems that the app is already live on both Google Play Store for Android and App Store for iOS devices.
Splatoon 2 will be the first game to be served via the new online service, but for now, there’s not much you can do other than download the app in preparation. The early release of the app is presumably meant to reduce the load on their servers leading up to Friday, July 21, when the service actually launches.
You’ll need to use your Nintendo Switch account to log into the app, and once you do that you’ll be able to enjoy the full range of online services. At the moment, we recommend that you download the Nintendo Switch Online app and install it on your device so you can avoid the last-minute scramble, which may congest their servers.
The early release of the app is a good thing considering what happened in the past with online games like Pokémon Go. A server outage is a good sign of heavy traffic, but not the best of experiences for the user.
More on Nintendo Switch Online as it breaks. We’ll update this article as we get more information.