Overdo is a menu bar app that lets you quickly and easily schedule deadlines.
TinyCal gives you easy access to Google Calendar or Apple Calendar, straight from the menubar. Add events, reminders, lots of options. TinyCal can show multiple months, use custom calendars, show holidays from many countries and multiple personal/business calendars.
See your day at a glance. Up Next puts your next appointment in your menu bar, with the time remaining until that next meeting. Works with Google and iCloud calendars.