Need advice with application process for new tenant

[Chris B.]

I have a few rental properties and always used an agent to do credit checks and rent them out. One property, a boyfriend and girlfriend signed a 1 yr lease. Then he moved out and she found a roommate and signed a 6 month lease (ends May 31st). My agent did me a favor for free and did the credit check on the new roommate when she moved in. Now she's moving out and she found another new roommate. I don't want to ask my agent for another favor to do the check on this new person. My question is. Is there a standard application I can use for this new tenant to fill out available, and any recommendation of site to use for background/credit check? Thanks so much, Chris