I love Shortcat but it's too slow to be usable on my i5-based MacBook Pro. I have been using Wooshy instead, but I'll be checking out mouseless after seeing it mentioned here.
I'm not familiar with Wooshy, so I'll have to check that out. Shortcat doesn't receive updates and for years there has been an indication that it would move from beta to licensed software (which I would happily pay for!), so I live in constant fear that it's on the road to abandonware.