There is a mobile version of the forum. It should automatically put you to the mobile version when visiting from a mobile device, but you might have changed your settings. Try this:
User CP > Edit Options > Tick the box "Use a mobile version if I visit from a mobile device?"
If you're looking for an app, try Tapatalk.
User CP > Edit Options > Tick the box "Use a mobile version if I visit from a mobile device?"
If you're looking for an app, try Tapatalk.