If you have questions about the Android API, please search Android API Reference page.
Stylus page talks about input events related to tablet, specifically Wacom Intuos, on Chromebook.
For note-taking apps, please check this page to register your app as a note-taking app or test it without a stylus.
Overview – Information on the Android API
Basics – Details on tablet specific Android API
Reference – Links to the complete Android API packages and classes
FAQs – Useful Android programming tips
Sample Code – Full Android API demo sample