Lock your phone

Press and hold on the lock screen and follow the prompts to edit the screen

Tap on 'Customize'

Tap on the area underneath the time to add a widget and if you scroll down, you will find Medisafe listed here.

Tap on 'Medisafe' then drag and drop the widget.

Once you have placed the widget, tap 'Done' on the upper right corner

Select 'Set as Wallpaper Pair' to save the changes.