Sidekick will update automatically upon opening if you're connected to the internet.
If you've been using it offline and would like to be sure you're using the newest version, open the Sidekick App while connected to the internet. Click the small present (gift box) icon on the top right of any PLAY screen (between the bug report (bug icon) and account settings (gear icon) buttons.)
If you're running the most current version of the app, the top left of the Updates window will say "You're up to date!" If you don't see that message--or you want to double-check--click Check for Updates on the top right of the Updates window.
If for some reason you need to uninstall Sidekick and go to sidekick.tv to download and install the latest version. Don’t worry — you won’t lose any of your settings or files. They’re safe and sound.