I'm using an Arduino Micro as an isp programmer to flash the assembly code into the atmega168. Here is a good site that shows how: Arduino Micro as ISP Programmer
If you're using a Mac you'll need gavrasm to compile the AVR Assembly code. Here's how: gavrasm
Also, you'll need the avrdude toolchain, which is pretty easy to find.
If you want to modify the setup data for the nRF8001 you'll need nRFgo studio which you can run on Mac with Wine. Here's a video shot by Tom Igoe: nRFGo for Mac