Niibe revised the design of Flying Stone Tiny (FST-01) for STM32F103TB, which is small enough.
It was not under consideration before, as he thought QFN soldering were very difficult. But now (for him), QFN soldering is not the thing to be avoided.
The photo is the one, it's built by DIY reflow soldering and hand soldering.
Please vote for FST-01 at the site: http://www.seeedstudio.com/wish/?p=783