A bit of a shameless self-promotion 
I wrote two libraries for two interesting sensor chips, first is AS3935 lightning detector chip, that can warn you about coming storm while it is still 40 kilometers away and the second in high dinamic range 16bit resolution color and light sensor chip TCS34717. Both libraries in my opinion are interesting in the way communications are implemented, library code does not access any other library, like SPI or Wire, directly, but rather relies on user sketch to provide functions to communicate over SPI or i2c bus, which makes them usable with almost any imaginable setup and scenario.
Both libraries can be downloaded from my github - https://github.com/raivisr?tab=repositories
And break-outs if anyone is interested in these, can be purchased here - https://www.tindie.com/shops/TAUTIC
