Best accounting software to track rental property income/expenses

[Alex Cons]

Hey BP, 

Tax season is right around the corner and another year went by that I did not track my bills! I would like to find a software that I could start using that will help me track my real estate income and expenses. 

I self manage my own units and I want to set up good tracking habits early on with a few rental units so that I can scale in the future. I would like a software that I could also use on my smart phone and under $15 a month. 

Any suggestions that are real estate friendly?