Getting application fee and mysmartmove site

[Vannak Kann]

Hi all i have a couple question about renting my house:

• I just give a tour to a couple who show interest in my house, however i only ask them for email/phone and name.
• I don't have a rental application yet, however i plan to use MySmartMove.com. I plan to use my card to run the application, how should i approach asking for the application fee. Do i need to give them any receipt for the application fee, or just ask for it that verbally tell them that it's non refundable. 
• If i use MySmartMove.com do i really need a written application at all? Thanks