Massplanner(the program itself) is hosted on your PC. Just the verification of license uses the a remote server (and that allows/prevents usage of the program, since its subscription)Unlikely. Followliker is hosted on your own computer/VM, instead of MP which is hosted on their own servers
Followliker is hosted on your PC. It too uses external website to make verification of your license. But difference is that since its not subscription(its one-time payment) and doesn't need to keep verifying your license. It seems that recent versions, if even license server goes down, program keep running. (I don't have followliker, but some user said that).
Really "scared"/sceptical about purchasing followliker, because it can have the same fate as MassPlanner. And it "could" still run, but after some IG updates, it would stop.