Just curious... why would you want to do that even if you're stuck? This is more of a quick brainstorm method, I don't think he's even looked to see if the domain name is available at this point.
Also, I'd rather have something like "getflint.com" or "flintapp.com" than "flnnt.com" or something. When you start getting into cutesy abstractions like that it becomes hard to remember.
I don't know about Flint, but many words already have the getname.com and nameapp.com domains taking. You can find more luck if you add hyphens though, but that makes for a pretty ugly domain.
Even .org and .net domains (which I don't mind, and prefer to ccTLDs) are getting sparse.
Also, I'd rather have something like "getflint.com" or "flintapp.com" than "flnnt.com" or something. When you start getting into cutesy abstractions like that it becomes hard to remember.