You can double tap on the lamp control you want to edit or tap ‘edit’ on the top of the screen in ‘Lamps’ tab and then tap the lamp control you want to edit. In the ‘Edit’ screen you can change the name and the icon of the lamp control. You can also assign different Modes (see question below for the explanation of a mode) for the lamp.

Under 'Lamp Settings' It is also possible to change settings for Smart Switching/Push Button and Startup State.