BetterTouchTool and BetterSnapTool are fully compatible with the current version of macOS Mojave!
In case BetterTouchTool or BetterSnapTool don't work on your Mojave installation, try to go to System Preferences => Security & Privacy => Privacy => Accessibility. Then delete BTT / BST from that list and add it again.
In case your license has expired and doesn't receive free updates anymore, you can download this version: https://bettertouchtool.net/releases/btt_2.428_recovery_mojave.zip. It doesn't contain the new features or improvements, but I back-ported the fixes to make it work on Mojave. Of course I still recommend to upgrade your license to receive the latest and greatest updates :-)