Look for Roblox and then tap the Update button next to it. If multiple updates are available, you can perform a simultaneous update by tapping on the Update all button instead.

Downloading Roblox for iOS and Android devices Image via Roblox Corporation The system requirements for Roblox on iOS and Android devices aren't too crazy.

Find out how to update Roblox on Mac, PC, Xbox, PlayStation, and even mobile devices in this helpful article.