Practical IndexedDB applications with code & explanations

Practical real-world applications with both code and explanations are hard to find. My compilation of the ones I've gone through (funny that the first three I've found so are are TODO apps) and liked:

• Paul Kinlan's article in HTML5 Rocks (a Google project) "A Simple TODO list using HTML5 IndexedDB" was first published in 2010 and then updated in 2013.
• TODO app - Chapter 5 of the excellent book HTML5 in Action, Mobile applications: client storage and offline execution, has a 30-page step by step explanation of a TODO list web application. This chapter is available as a free download in PDF format. The source code of the all the apps explaining various HTML5 features, is available on Github.
• Building A Simple Cross-Browser Offline To-Do List With IndexedDB And WebSQL - a Smashing magazine article by Matthew Andrews shows how to make a simple offline-first to-do application

to be continued...