We don't have a native app, but the website is usable on mobile. You can add it to your home screen by following those steps:
For iPhone and iPad (using Safari)
Open the Safari app and navigate to the website you want to add. (Note: This specific feature only works in Safari, not Chrome on iOS).
Tap the Share button at the bottom of the screen (it looks like a square with an arrow pointing up).
Scroll down the share menu until you find Add to Home Screen, and tap it.
You'll see a preview of the icon. You can edit the name of the shortcut here.
Tap Add in the top right corner. The website will now appear on your home screen.
For Android (using Google Chrome)
Open the Google Chrome app and navigate to the website you want to add.
Tap the three-dot menu icon in the top right corner of the screen.
Tap Add to Home screen from the dropdown menu.
A pop-up will appear. You can edit the name of the shortcut here if you want it to be shorter or easier to read.
Tap Add.
A final prompt will appear. Tap Add to home screen to have it placed automatically to your homescreen.