Swipe Pro (formerly iSwipe/SwipeIt!) is designed to be a powerful one-stop solution for mobile payments on the phone.  Now for international merchants also.

uCharge is for merchants that are just getting started and has less features, but is cheaper and simpler. It does one thing (charge credit cards) and does it well.

Swipe Global (formerely iSwipe Global) is for international merchants who need to accept money in other currencies.  This program is being replaced by Swipe Pro.