Break Timer lets you set custom break times in your browsers so you are not constantly working on your computer.
Handre allows you to create reminders out of your drawings on your devices.
Es.gy reminds you of the links you stumble upon by email.
OutStanding is a web based app to remind you to stand up at a certain time interval in your browser.
Cut Your Time helps set alarms to remind you of your tasks using various options.
Mater runs a 25 minutes timer followed by a 5 minutes break in the menu bar of your Mac.
RestStop reminds you to take a break after you have worked for a certain time on your PC.