Knowing what city and state you are located in goes a long way to getting an appropriate response.Contact the state "Mobile Home Park Owners Association" and ask for their advice.If you have a valid lot lease, and you never released the tenants from the lease, they are still in possession and in my non attorney opinion they owe you the lot rent until the home is removed or title is transferred to you.Most mobile home movers will not move a home without seeing the title.

Also, what methods do you use to streamline your business?

Basically, try to streamline without calls first!

I'm trying to be fair to the guy, but also want to streamline my business here.

and I'd send them all a text, too, saying you won't be sending them payment requests anymore, you'll just be texting them the amount due.If you can streamline letting them know what they owe, then it's their responsibility to pay you in whatever way you've agreed.If you're in CA, I don't think you can charge a service fee, unless it's an actual out of pocket cost. 

Looking for a place, maybe the place you're moving into changes move-in dates on you, you're trying to line up movers on and on. 

I know how you are feeling but good thing is your current tenant is move out but can't find mover so help current tenant in finding mover.Secondly, you should have in the LA that, if the new tenant can not move in X days then they should change the lease date or terminate the lease date.Thirdly based on the current tenant situation inform new tenant about your current tenant problem.Just relax and all will be fine!

I'm looking for an app that can streamline this activity.

A free month's rent and the cost of hiring movers, maybe?

I personally, would rather have a contract set in place before I show up with movers I'm paying to stand around outside while I go through a million-page contract and addenda with a manager.