For the last couple of apps I've made, I've been creating a sort of mind map to help me come up with the name. Finding a good name for an app is hard, but having a somewhat formal and repeatable process has made it much easier for me.
I say "sort of" mind map, because there aren't really any strict rules I follow about organization/hierachy/line length/color/etc. It is more of a free association with a bit of structure. I write any words that come to mind, and connect them in whatever way makes sense. I try not to filter myself at all, because while I know I won't use it as part of the app name, it may lead to something that will.
Here is an example of the map I created to name my most recent app, Flint, a Campfire client:
Excuse my sloppy writing, I usually create these fairly fast, and I'm the only one that ever needs to read them.
In this case, the words were anything related to camping, fire, or chatting. I could have taken it much further, but I found a few names I liked, and settled on Flint. Note, this is designed to create the kind of names I like for apps. Short, preferably one word, that has some connection to what the app does, however thin that connection is.