Even if you have the latest OSX version, the Check for Updates link should still be clickable.
If it's not, there are a couple things you can check for.
- If you have selected to automatically check for updates, you may need to just quit and restart Biba.
- If Biba is in the process of checking for an update, or if it's already checked and the dialog is still open (possibly in the background), the Check for Updates link will be inaccessible. Check for and close any open Biba dialogs.
- The other possibility is that you're running Biba from the dmg, rather than the installed app. To remedy this, just quit Biba, then when you search for it in Spotlight, select from Applications, rather than Top Hit, which could be either the app or the dmg. When you relaunch Biba, the Check for Updates link should now be clickable.