Is Blendr any good?

I've heard about Blendr, the social networking app that focuses on dating and hookups, but I'm not sure if it's worth checking out. Can you tell me more about the app and whether or not it's any good? Is it user-friendly? Does it have a lot of active users? Are there any unique features that set it apart from other dating apps? And most importantly, is it SAFE to use? I'd love to hear your thoughts and opinions on Blendr.