Add shortcut to Galaxy S6 Lock Screen

A

AC Question

This is a basic question but I have downloaded a bunch of apps and they have been frustrating.

All I want to do is add a shortcut to one specific app on my lock screen. It is important that this app icon is visible on the lock screen, not buried in a menu.

Ideally I would be able to launch this app even if there was a passcode on the phone.

So far all the app lock screens I've downloaded seem to do a hundred things, but not this one thing well. I used to use LockMenu on my old phone but this is not compatible with my new one.

Can anyone suggest an alternative?