This chapter focused on an easy but useful project and taught you how to use IR to transmit and receive data to and from Arduino. There are many different applications of the basic circuits and programs that you learned here.
On the iOS platform, you learned the very basics of capturing sounds from the device microphone and the DSP (digital signal processing). This allows you to leverage the processing capabilities of the iOS platform to expand your Arduino projects.
The next chapter will be amazing. You are going to open your garage door magically; you don't even need to touch your iOS device to do this. You will also learn a lot about the iBeacon technology. Your imagination will be your only limit!