Just received the NanoFlyer v2.0 boards from Oshpark and put it together with my hot air station and hand soldering. I have got best results on soldering QFN chips by first tinning the pcb pads with solder and flux, as well as tinning the chip pads and then heating the board with hot air from the bottom side. I believe it works best as there is no air to push the chip around and pure solder tension puts the chips in place, so the chips aligns on the board nicely too. Having a good flux gel is important. I did not notice I before I bought a tacky no clean flux and it actually does leave some sticky resedue on the board. You will need to clean it just for the sake of making the board looking cleaner and nicer, it does not create shorts or anything though. Similar technics can be used to solder other smt parts if you are not using solder paste. Just tin the pads, put some flux and place the parts. Then heating the board from below would put the components in place nicely. Even if you use solder paste, heat the board with hot air from bottom of the board, or your tiny smt parts will fly off when using a hot air station.
This board has the MPU-6050 accel/gyco chip and HMC5883L magnetometer chip on-board. The second TX/RX port, I2C ports are also populate for extensibility. The board mesures 30mm X 30mm (1.2in X 1.2in). Almost all of the IO pins are populated out on the board with with soldering pad or by connecting it to LEDs. The board has 5 indicator LEDs and one is PWM capable. I am trying to find any support for the ATMega256RFR2 chip in WinAVR or guides on how to add support for this to the existing WinAVR ditribution. As it is fairly new to the market, I have not got any luck on that yet.