Ultimate Custom Widget (UCCW)
Ultimate Custom Widget (UCCW) is an Android power user favorite -- in fact, it's a common thread in many of the most impressive Android home screen setups.
UCCW allows you to create practically any widget imaginable by using its WYSIWYG editor. Widgets can include elements like clocks and weather panels as well as dynamic info about missed calls, unread emails and new text messages.
You can also download ready-to-use UCCW widgets that other people have created; just search the Play Store for "UCCW skin" to find plenty of interesting possibilities.
UCCW is a free download.