beSocratic is a tool not specifically related to CI's, but is a helpful tool nonetheless. 

"BeSocratic is an online assessment system focused on addressing these two goals, i.e. providing students with proper feedback and teachers with meaningful analysis. On the student side, BeSocratic is able to recognize student drawings and respond with meaningful feedback based on the drawings. On the analysis side, BeSocratic contains sophisticated clustering techniques which group students based on the similarly of their submissions. This allows teachers to only look at a small subset of student submissions and quickly get an overview of an entire class's understanding level."