Please note, this blog entry is from a previous course. You might want to check out the current one.
Create appropriate icons for your two tabs. The icons are 30×30 and are pure alpha channels (i.e. they are a “cutout”). Search the documentation for more on how to create icons like that and set them.
Create the icons using your favorite graphic program, add them to your image assets and choose them as tab bar icons:
The complete code is available on github.