Bluetooth to Terminal on Android

I'm looking for a suggestion on a bluetooth device for an Arduino project. Ideally smaller than a full size shield as is it would be a for a smaller imbedded project.

There are a ton of posts but not much in the way of "I tried this hardware out and it worked. Get you one!"

I'll take care of the code, etc I just want to be confident that what I buy isn't going to be more trouble to set up than necessary. I'd appreciate any info.