For example, do you have any favorite...phone apps (chat, photo, listings, calculator apps), online services (answering services, screening, listings, signing, rent), or hardware (which smart phones, cameras, door bells, voice controls, 3d walkthroughs, lockboxes or smart locks, wifi services, tv, etc)Full disclosure...

If the market falls, all we have to do is hit the sell button on my smartphone.

I have buddy grew up in the Northside, he says the foot traffic/drug dealers are less of an issue since the dawn of smart phone and apps.

@William GravesBefore walking a house, I estimate using rough $/sqft from previous experience.If that gets me near a purchase price that I think can be negotiated, then I'll go visit the property.Generally when I first walk through the property I estimate by taking notes on this spreadsheet:https://www.biggerpockets.com/files/user/kubaf/fil...While I'm there I am also using my smartphone to record the entire walkthrough, because I always refer to that video later during itemization.Then I go back and rerun my numbers.If the numbers are still in the ballpark I'll make the offer.If the offer is accepted, at that point as part of the property due diligence I will then spend the time to itemize the rehab costs and solicit bids based on the itemized scope of work.

On a typical longer-term residential rental home, a smart phone will work great.

You can watch or listen to the podcasts on your computer or smartphone.

You can deposit checks via your smart phone nowadays with your banks application, so its not that much of a hassle.

I don't want to give the tenant any reason at all to allow a potential small problem to go unaddressed with the possibility of it becoming a big problem.Now, if your goal is to minimize the headaches of having to go out to the rental property everytime the tenant thinks that there is a problem, then ask the tenant to send you a video or picture of the problem using their Smart Phone (which it seems EVERYONE has these days). 

People are still people even if they use smartphones now instead of landlines. 

You can join the virtual sessions from your smartphone or watch the replays when your schedule allows.