Hover Zoom - Enlarge thumbnails on mouse over.
Cron - Cron Calendar.
Imagus - The extension is intended to complement image features that (I think) is missing from Opera by...
Vimcal - Vimcal is the world’s fastest calendar, beautifully designed for people who work remotely and live in their calendars.
Image Max URL - Help find larger or original versions of images, including a customizable image popup feature
KosmoTime - The to do list with super powers