I2C Protocol Analyzer
EasyI2C - Xtreme Engineering LLC
It's simple to find an I2C-style bus within arm's reach. Every computer, monitor, television and cell phone has it. Most microcontrollers directly support this protocol as well. Even so, the I2C protocol has many subtle nuances that are hard to grasp and easily forgotten. EasyI2C (TM) helps you to figure out exactly what is happening, without having to examine huge waveform trace capture files or set up complex tests.