This project is based, conceptually, on the excellent IR-Blue Kickstarter from a few years ago (although it uses none of the same code).
I had thought I remembered all Adafruit code being MIT-licensed, but upon checking I seem to be wrong. I'm using a version of Adafruit's SSD1306 driver library that I modified for the RFDuino's ARM architecture...you can find a link to the modified library in the "External links" part of the project page.
The only other code that I think might be worth citing is the demo Arduino code that is included in the Grid-Eye datasheet from Panasonic - I couldn't find a license on that code, and I don't think I'm copying it linearly, more just using it as a reference.
I'm always anxious about attribution because I don't want to offend of slight anyone - all the electronics and code that I am able to do is only by virtue of many, many others sharing their work, so I'm hoping to participate in kind.