“You should sell it.” That is what everyone says about old phones. But my four-year-old Android was worth maybe $40 on eBay. The screen had a scratch and the battery lasted six hours. I was not going to go through the hassle of listing, shipping, and hoping the buyer did not complain.

So I turned it into something useful instead. Here are the three best things you can do with an old phone.

Dedicated Security Camera

Download a free app like AlfredCamera or Manything. Mount the old phone in a window facing your front door or driveway. Plug it in permanently — you do not need the battery to last. Now you have a live-streaming security camera with motion alerts, night vision, and two-way audio. Total cost: zero dollars.

I set mine up watching the front porch. When a package gets delivered, I get an alert on my current phone. It is not as polished as a Ring doorbell, but it also does not cost $100 plus a subscription.

Dedicated Music Player for the Car or Garage

Load it up with downloaded playlists and podcasts over WiFi, then leave it permanently connected to a Bluetooth speaker in your workshop, garage, or car. No notifications interrupting your music. No calls coming through. Just a pure music device that does not drain your real phone’s battery.

Kids’ Device for Games and Learning Apps

Wipe the phone, set up a restricted profile, and install educational apps and simple games. No SIM card means no calls or texts. Parental controls limit screen time. When it gets dropped on the floor — and it will — you do not care because it is a $40 device, not your $900 daily driver.

This was the best use for mine. My seven-year-old uses it for math games and drawing apps. The screen is scratched anyway, so I genuinely do not care if she adds a few more.