I think you should really think more about it. $0.99 is great and all for an app but you could be earning commissions on domain name registrations at the same time.
I'm trying out your app right now for a vexing domain name brainstorm I've been having...
Yeah this definitely seems like a great feature to add. Initially we were just enjoying the words / not thinking of it as too domain-centric, but at the very least being able to quickly whois would be nice.