When I had to choose a name for my app, I couldn't come up with anything good. I think I changed the name 3 times in the first couple of months, until I found something that I kinda liked. But I was never really satisfied, until I came up with a good name after two years. Then I released a new version of my app with a new name!
Coming up with the idea is terribly difficult... but I can tell you the secret of a good name is that it's polarizing. People should either love it or hate it. If people are like "meh, its okay" throw that one away