Memento Mori for Mac alternatives and competitors

Memento Mori is a menu bar app that shows you your exact age and how it is constantly increasing. Or it can show how much time you have left. It is a reminder of the finitude of one's time on this earth. It is a tool to create meaning and urgency. An encouragement to use your time to the fullest. Use every second you get as well as you can. Go!