Have you ever wanted to know when you last changed your air filters? Your contacts? Your hot-tub water? If so, Checkov is the app for you.

Some things you want to keep track of just don’t belong in your “real” calendar. For instance, I’m working on getting my US Coast Guard captain’s license, and I just want to know how many “sea days” (day’s I’ve spent four or more hours on the water) I’ve had. Easy, I created a Checkov calendar called Sailing and started checking off days. Same for my fasting days, oil changes, etc.

Let’s face it: keeping track of these things is a pain, but they’re useful to know. So I developed the simplest possible app to help you keep up with them. All you have to do is toggle the day it happened, and you’re done! Also, you can get basic statistics about your calendars within the app, and you can even export the dates in comma-separated value format (CSV) if you want to do some more serious analysis.

There are no ads in the app, so the only money I make from it is the purchase price. Isn’t it worth less than the price of a latte to know the last time you groomed your dog? Changed the water in your aquarium? Sure it is!