Digital photo frame. To turn your smartphone into a digital photo frame, just install an app like Dayframe, load a selection of your favourite photos, sit it in an upright dock and let it roll. This is a sure-shot way to impress the guests and keep the memories alive at all times.
Baby monitor. You do not need to spend huge amounts of money so you can keep an eye on your precious little one. Apps like Dormi and the simply-named Baby Monitor transform an old smartphone into a baby monitor, while streaming videos and audio to your current device.
Security camera. Take advantage of your device’s camera by turning it into a Wi-Fi-enabled security camera to protect your home. Apps exist that are motion-sensitive and will email you with photos.
Alarm clock. Who uses an analogue clock these days? Take your pick from the thousands of clock apps in Google Play Store, buy yourself a cheap smartphone dock and you have got an infinitely customisable alarm clock to sit beside your bed.
Video chat terminal. Set up your old Android device with apps like Google Hangouts and Skype and use it as a futuristic terminal for face-to-face communications. Think of it as an extra extension for your office or living room. As long as it can handle GSM and GPRS, it should be fine.
Apart from these, there are many other ways you can make use of your old Android device. So get your device out and start tinkering with it.