You just need to take a video through the app (or import from your photos) and trim the video down to 1 second. The video will stay on the calendar inside of the app. You can preview just the one day - or all the days you have created so far.
What a great idea to see what happens in a whole year in 365 seconds (or 366 if it is a Leap Year).
Embedded below you will my 2 second video of these past 2 days (followed by how they look as a GIF). Then imagine 365 of them - very cool!!
Click here to see helpful videos the site has created on YouTube.
Just an FYI the app does cost $4.99.
Enjoy making those memories!