Before getting started on Processing for Android, make sure you have Processing installed.

1. Open Processing
2. Click on Add Mode... located in the top right of the window:
3. Search for "android" in the Contribution Manager and choose the option that has the author "The Processing Foundation" and click Install
4. Once the installation has been complete, switch the mode to Android
5. This window below should pop up. If you do not have the Android SDK, click on "Download SDK automatically" to install it. If you have already installed the Android SDK, then click on "Locate SDK path manually". 5,5. For me, I located my SDK path at /Users/my-username/Library/Android/sdk
6. You're done!