There are only so many no-brainers in life. A popsicle in the summer? Yep. Petting a cute dog when it comes up and says hai to you? You bet. But when it comes to fitness, motivation and choices—like what to do and for how long—can get in the way of actually giving something the green light.

Finally, an exercise “duh” has emerged: Meet Shimmy, a new app made to help people stay active during the holidays. It’s designed as an advent calendar, so there’s a new workout for each of the first 25 days of December leading up to Christmas, though you of course don’t need to celebrate Christmas to get in on the action.

Ready to get to the even better stuff? First of all, the app is free! No financial commitment required. Second, each workout is only seven minutes long. Truly, heating a frozen meal in the microwave can take longer than that. And finally, if you complete all 25 workouts, Shimmy will donate $25 to charity. Win-win-win!

The workouts range from dance cardio to HIIT to yoga and more. You can create gifs that represent the workout you just did, and fill out an emoji calendar to mark your progress—then share them on social media.

Shimmy is a 501(c)(3) nonprofit that’s funded through charitable donations. It was co-founded by Kaitlyn Krieger, who also runs the Future Justice Fund with her husband Mike Krieger (one of the co-founders of Instagram), and Nina Samarguliani, who most recently led product design at Tonal.

Their workout advent calendar is raising money for three charities, splitting the funds between all three: the Chris Paul Family Foundation, which works to create equal opportunities for families in “education, sports, and life”; Baby2Baby, which provides clothing, diapers, and other necessities to children living in poverty; and Bring Change to Mind, which is working to end stigma around mental health issues. Chris Paul and Baby2Baby ambassador Jessica Alba are both promoting the Shimmy challenge.

The mini-workouts are meant to be a “fun-sized” way to get your blood pumping for the two-for-one good causes of charity and your own health. That certainly makes for some happy holidays.