A reply from the programmer:

"if we are talking only about heads-up I'd say that Coffeecalcs can do everything that all of that programs can do for heads-up, and even more, for example ICMIZER has a more advanced push/fold calculator overall but if we are talking about hu CCs does exactly the same things but is much faster and you can use weights with preflop ranges (icmizer doesn't allow it). It's the same with Flopzilla, it can break your range into smaller parts (set, tp, ...) street by street, but CCs can do exactly the same thing with two ranges at the same time and show you how those ranges plays against each other on the equity distribution chart. There is also no alternative to the preflop strategy planner."