15 free Android widgets you must have

Widgets have been a staple of the Android operating system ever since they were introduced in version 1.5 of Google's platform. They are a great way for Android to show off its customization flexibility, allowing a home screen to be made as functional as possible and tailored to the user's needs.
As always, the comments section below is open, so feel free to let us know which are your favorite Android widgets, or if you know of a great Android widget that we should have included on the list.