BetterTouchTool is using oneskyapp.com for all translation activity.
If you encounter a bad translation, typo, or something like that, you can either report it here in the forum, or directly go to http://translate.folivora.ai/collaboration/ search for the phrase and fix it yourself.
Also if you want to help with translating (I wouldn't recommend that, it's a lot of annoying work) you can also do that via http://translate.folivora.ai/collaboration/.