Breathe new life into your “obsolete” smartphone by using it as a smart home gadget

Just because your old smartphone is a couple generations old doesn’t mean it can’t be put to good use. When you get down to it, even the most outdated phone is still a palm-sized computer stuffed with advanced sensor tech. So instead of throwing it away or reselling it for less than what you paid originally, why not repurpose it?

There are dozens of incredible Android and iOS apps that can transform your phone into a useful smart home fixture, as well as a myriad of low-cost “appcessories” that can add extra functionality to your device. Below you’ll find a quick roundup of the best ones around.

Manything (iOS)

Manything is a free iOS app that can convert your iPhone, iPod Touch, or iPad into a Wi-Fi-connected security camera. Then, you can use a second iOS device as your mobile monitor or opt to keep an eye on things from the Manything webapp. But it’s more than just a security camera; it’s also got it’s own IFTTT channel, so you can link it to a huge range of webservices and connected devices. For example, if you’ve got Philips Hue lights in your house, you could set them to turn on automatically whenever Manything detects motion — making your phone act as both a motion-activated smart switch and a handy home-security tool that makes it look like someone’s home.

Salient Eye (Android)

Much like Manything, Salient Eye turns your phone or tablet into a network-connected security cam; the only big difference is that it works with Android devices instead of Apple ones (though an iOS version is in the works). It’s completely free to download and use and comes with a boatload of useful features, such as auto-capture on motion detection, email and text alerts, a sound alarm, and a decent chunk of free online storage space. And the best part? It works with any phone running Android 2.2 or higher, so no matter how old your brick might be, it’ll still be able to run the app. Just don’t expect crisp, 1080p video playback from your first-gen Samsung Galaxy.

Cloud Baby Monitor (iOS)

There are a handful of different of baby monitor apps in the App Store, and while the vast majority of them are nearly indistinguishable from your average security cam app, there are a few that boast advanced features and functionality that set them apart. Cloud Baby Monitor is one of those apps. In addition to live-streaming video footage, the app also supports two-way audio transmission so you can hear (and talk to) your baby; musicplayback so you can play your little bundle of joy a lullaby; and adjustable brightness controls so you can keep an eye on the crib in complete darkness.

Dormi (Android)

For a one-time price of just seven bucks,Dormi will take any Android phone or tablet running Gingerbread version 3.2 or greater and put its Internet connectivity and advanced video and audio sensors to good use. Once you’ve got it installed, you just plug the device into the wall and let it run like a regular baby monitor. From there, you can use your primary phone to monitor audio or video at any point, or simply configure the app to send you automatic alerts when your baby wakes up. It constantly senses ambient noise in a given room, so as soon as your little monst — err, bundle of joy — wakes up and starts crying, you’ll know.

Bemo (iOS/Android)

Designed by Arizona-based startup WiseLabs LLC, Bemo plugs into your old iPhone or Android device and transforms it into a fully functional smart thermostat. The device itself is only about the size of a credit card and works as a sort of bridge between your phone and the HVAC wiring in your wall. Once you’ve got it all rigged up, all that’s left is to download the Bemo app and fire it up. WiseLabs’ custom-built software can perform just about all the same functions you’d find in a purpose-built smart thermostat from Nest, Honeywell, and the like — remote control from your main smartphone, smart scheduling, habit learning, energy monitoring, and even proximity-based activation settings that can turn on the heat or AC before you get home.

Rico (iOS)

Rico doesn’t necessarily need a smartphone in order to function, but when you pop in one of your old devices, it transforms into a highly-capable smart home hub. On it’s own, a slew of embedded sensors allow the device to operate as a motion detector, thermometer, humidity sensor, smoke and carbon monoxide alarm, and even an Internet access point for connected devices. If you happen to have a dusty old smartphone to put inside, however, you can give Rico a handful of additional functions. Put one inside, and the device can take advantage of your old phone’s speaker, microphone, HD camera, 3G connectivity, Wi-Fi, BlueTooth, and processor.