I'd like to provide potential tenants with some sort of automated system where they can sign up for an available time slot online or in an app. 

In college I dropped my check off through the slot and then my roommate and I got a call that I didn’t pay.  

I'm not solo, but my husband didn't know a phillips from a slotted when we married. 

Also in the town ordinances, there are parking slot and green space requirements.

My HELOCs are in the mid to high 3's. Lots

@Kenneth Mims you would be looking for a blanket loan, however if you don't need the additional mortgage slots it may be better to refinance them each individually, but it will depend on many factors including the lender.

That requires a lot more effort than putting a few quarters in a slot and pulling a lever.  

Preferably the 10AM to 11AM slot. 

If I had to collect 14 rent cash payments at once in the neighborhood my properties are in every first of the month on the dot, it's not a question of if I would get shot, it's when.In your situation you can build a strongbox on-site with a slot through a wall or door, maybe in a maintenance closet.

Are there slotted vents in the foundation wall?