I am a software systems engineer by profession, so writing my own calculator seems like the obvious thing to do :)  (Of course, seeing how others have done it can help me keep from making mistakes and it is free, so I did use it to double check!)

If you're in the market for accounting software as well, Buildium is what I use and I've been happy with their system and rent collection.

The terms of use of CARs software provider also prohibit providing blank or partially blank forms. 

Also, I don't think it's going to be too long before the software that handles the backend for these sites is commoditized, and will be available at almost 0 cost to anyone or any site that wants it.

I am a software programmer so I could develop a nice little system that could be used to gather this type of data.  

There are ways to streamline PM business processes with certain software programs, but PM entails physical work on the properties and relationships with people on the ground, always. 

We've been using some new software for Direct mail which I'm impressed with.

I am a huge fan of Charles Dobens "Multi Family Investment academy"  Have been a member for a few months now and found the information to be relevant, workable and accurate.On top of that Charles and his staff are extremely approachable and reachable by text or phone.I believe I have gotten more than my money's worth in just consultation time much less the videos, audio and software offered.PM me with any questions you may have.All the best.Michael

It will take you time to get this trust, esp. if you do not have the software to show them in 3D.

There are a few software packages that work well for this.