Nintendo Switch firmware version 6.0.0 is now out which means Nintendo Switch Online has now kicked off. The NES Online App is also available on Switch, but requires NSO membership to use.
Don't forget to grab controller updates for your Joy-Cons and plug-in your Pro Controller to get an update for that too!
The most important and surprising bit about the update is now you can access most of your account's games on another Switch! Nintendo Life has an article on how that works here.
For discussion about the Nintendo Switch Online service and its app, you can talk about those in this linked thread:
Edited by Ngamer01, 19 September 2018 - 07:02 AM.