When craigslist started charging me $5 to post my formerly free to post ads asking for cash handyman, it was still worth it and I’ve paid it many times.Facebook marketplace may gain market share, but its user interface isn’t nearly as good imo in terms of map-area searching for an apartment.

Cozy accepts partial payments by design, and I don't see any way in the cozy interface to prevent a tenant from doing a partial payment.

I like RA and I find their interface much easier to work with. 

Let me know if you've used these before or if there are others that would fit on this list.Richblockpoorblock.com: Has an interactive heat-map interface that tracks income, population changes, poverty levels, real estate taxes, owner occupancy rates and more.

The ease of use / user interface I think one of the more valuable components - meaning: how quickly can you learn to use it and integrate it into your business?

Smooth and easy to use interface that holds search parameters.

Has great and easy to use interface.

I don't have any problem with it's software or user interface. 

I personally think the BiggerPockets interface is good to use but could be greatly improved.

One that has a nice interface that's accessible by tenants, owner, subs, etc.