Android: There are some pretty neat clock widgets to be had out there, but if you don't like what you find, free app Make Your Clock Widget lets you make your own — either from scratch or from a number of templates.
Make Your Clock Widget does exactly what it sounds like, and it's pretty darn powerful. You can add all sorts of items to your widget (whether it be the time, full date, day of the month, day of the week, year), use different fonts, colours, and arrange them any way you want. It isn't that hard to use either, except for the touch interface, which can make it a bit difficult to place items precisely where you want them. Beware — you could spend hours perfectly crafing your clock widget without even realising how much time has gone by! You can also download some premade clock widgets from the gallery and tweak them as you see fit, if creating your own from scratch is too daunting. Check out the video above for a tutorial on how to use it.
Make Your Clock Widget is a free download for Android devices.