Announced today during the Splatoon 2 Nintendo Direct, Splatoon 2 will see the launch of SplatNet 2, an app available via Nintendo Switch Online. Players will be able to utilize SplatNet 2 to track their online stats and performance in online battles.
The app allows you to check out your last 50 battles, including your win to loss ratios for certain stages as well as the total area you've splattered ink all over, or your "lifetime inkage." There's also information like stage schedules, gear and stats you've used, and ways for players to keep in touch with their Splatoon 2 business while away from their Switches.
That all takes place via the Nintendo Switch Online app, which will allow players to invite each other to Private Battles, Salmon Run, Splatfest Battles, and League Battles as well as offer communication with players who opt in to voice chat. Obviously you'll need a mobile device to get in on the action here with a regular internet connection (you could presumably use your plan's data feature too, of course.)
Also, as seen in the Direct, it looks as though there's some sort of additioonal Miiverse-like functionality included where players can post artwork for other players and artwork on the ground and walls, as referenced in a previous interview with Game Informer between Splatoon 2 producer Hisashi Nogami and Lead Programmer Shintaro Sato.
If you're planning on making a big splash with Splatoon 2, you'll certainly want to take advantage of these new augments meant to make multiplayer even simpler. We've yet to try out the Nintendo Switch Online app just yet, but it sounds like it'll feature a fairly robust set of options.