We don't have a Sellar App, but you can make it function like one by adding it to your home screen.
Adding Sellar to your homescreen on iPhone
Using Safari, go to Sellar on your iPhone.
Tap the 'Share' button in the bottom bar of Safari
Tap the 'Add to Home Screen' option
Tap 'Add' in the top right-hand corner.
You can now launch Sellar from the icon on your iPhone home screen.
Adding Sellar to your homescreen on Android (or chrome)
Using Chrome, go to Sellar on your phone.
Tap the three dots at the top right of Chrome.
Choose 'Install' to install the app
Tap 'Install'.
You can now launch Sellar from your home screen by tapping the icon.