I track everything in an excell spreadsheet that I modified from a template i found online (also free) stessa.com is free app for tracking expenses that links directly to your bank account.As I scale I plan to move into a software but as of now I am fine with what I have and as you can tell I like free.  

I use the Evernote app for this type of thing.

It's free with BP-pro, and offers phone apps for both landlords and tenants.Good luck,Ruoqi 

Could be the location of the property and cell signal.

The Soil Connect app might be helpful.

Drama on top of more drama.Plumber fixed the toilet, which he says "may" be what caused the smell, but he personally smelled nothing.The tenant somehow, and I have no idea how, tracked down my personal cell number - bypassed the property management company and started calling me to complain about the fact it took three plumbers to fix the issue and how he shouldn't owe rent because of being forced to live in such an environment.Eventually I lost my cool because this guy was getting more and more aggressive on the phone, and I told him I would gladly approve his request to move.I don't think he expected that, because an hour later the tenant's mother called me (she doesn't live with him) to apologize on his behalf and talked to me about allowing him to continue living there.

Rental: the one I kept as a rental had a PP of $55K and cost $140K to rehab.

I don't think you can get previous landlords with a zillow app. 

I have found  mobile app called Clarem (www.getclarem.com) useful to build a plan and stick to it. 

Be sure your marketing and your application include whether you have a pets/no pets policy; assistance animal policy; ALL adults must complete application and will be named on the Rental Agreement; utility responsibilities; SD requirement; when and how various funds are due (app fee, SD, initial rent, etc).