There is not a downloadable app available yet. However, the 2026 website refresh does work extremely well on a mobile device. It was redesigned from the ground up to give mobile users an excellent experience. Look for dedicated apps coming in Q42026!
You can make a shortcut on your phones' home screen: in iOS, open up the site using Safari and click on the share button (the square with the arrow pointing up) and click on the "add to home screen" button. An icon will be created that goes directly to Undebt.it.