Hello!
There is a PPA GUI called Y PPA Manager, but I don't know quite what it could do/would do if installed and ran it on an LL machine. You could assign a key sequence to start it, I suppose.
When I add a PPA, I just cut-and-paste the PPA command into a terminal window from whatever site is mentioning the PPA. After all, just how often does a PPA need to be added?
73 DE N4RPS
Rob