There are some free apps out there but I would not rely on them.

When you post an image on a website or app (that you don't own) generally has a "Terms of Service" that give the owner of said website/app full rights to use your information in any way they wish. 

Picture a storage facility in which renters can lock and unlock their units using an app.

None of them really met our usual criteria but we decided after holding their apps for a while that if we got no better ones we would pick out the most qualified unqualified tenant.

What are some good and inexpensive/user friendly apps to help me manage my rental property?

Would love an app or a tool that I can reference quickly to determine what different properties would rent for.

Besides BP, what websites or apps would you recommend?

I see that there are several apps available that allow the user to accept calls and texts and even call out using a specified business phone number.

Paid app like deal machine a right off?

Ideally I would like something where you can list out the expected monthly or quarterly distribution and then every time an ETF comes through, I go enter the cell next to month/quarter and then it'll automatically add up everything to show how I'm performing on an annual basis.