If you visit many different programming sites and come across problems you'd like to solve later, and forget about them later, consider giving this chrome extension :
Upsolve tracker a try.

Upsolve tracker lets you - mark problems for solving later across various sites, and - also lets you add tags to the saved problems - view your pending and solved problems at-a-glance in your dashboard - reminds you the number of pending problems via a badge on the extension icon.

More features such as activity graph and alarm reminder are in the pipeline.

Suggestions/ Pull requests at github repo are welcome!