Ritual Path Magic ritual cost calculator:
http://gurps-monsterhunters.appspot.com
Although this is a web app (JavaScript) it uses the HTML5 manifest to cache the entire application in your browser's cache, which means it is accessible offline. Just visit the above URL while you are online, and after the app loads, bookmark it. You can then access it even if not connected to the net by loading that bookmark.
It features a power-gathering random dice roller as well - just enter the amount of energy to gather, and the caster's effective skill, and it will generate all the rolls needed to gather the energy, tracking the amount of time needed, energy gathered on each roll, number of quirks, etc.