This is an app that I use to keep track of the days that I practice Ashtanga yoga.
People who practice Ashtanga aka Ashtangis rest on Moon Days (days with circle). Here's why. We also designate one day during the week as rest day. For me, it's Sundays. Female Ashtangis rest on ladies' holiday (red days).
Below is a screenshot of my practice last November. The days with blue checks are the days that I practiced.
I started using this app since May and update it daily. Many thanks to my friend, Reyra, who recommended this to me.
This app is free to use. You can download it here.