I’m planning on renting out some rooms soon and was wondering besides craigslist and cozy.co what are some other good sites or apps to find and screen tenants?

Good question, I asked it just the other day with little interest. Rentprep was mentioned in Brandon & Heather's book on Rental Property Management. Cozy is another one, probably the route I'll go when I have to find my first tenant. And I heard of Rentec, but don't know the cost. 

@Ryan Dunnie   I would recommend checking out the landlord resources tab on BiggerPockets.  BiggerPockets has recommended screening services on there which you can look into to see which service best fits your screening needs.

I would also recommend setting strict screening criteria for what you are looking for in a potential tenant to steer away applicants who would just be wasting your time.