Yup,having to come up with many domain names as yourself I've become quite familiar with suffixes and the ability to also use them in compound fashion. Not to be too snarky but just google suffixes and look at the usual suspects like wikipedia and the dictionary sites. You'll see how much we've mangled English from the Latin roots.
How about using the word fever instead of throb? Or perhaps incorporating the suffix -ality or -ity to represent "the state of" the app?