Queue points, queue types and selection by queue time, without a queue system of your own.

Each queue has its own points, and you choose whether they reset when someone signs a lease.
In My account, or when they apply for an apartment that is let by queue points.

Queue time counts in all your locations, not just the city the person applied in.
Applicants are ranked by points, and the points that decided it are saved when the lease is signed.
You choose per queue whether points start over when someone gets a lease.
Import the list, and each person is invited to take over their place with their queue time kept.
Once a year, people in the queue confirm they are still looking, so the queue does not fill up with inactive places.
Someone who joins through your queue only sees your queues, until they choose more themselves.