1. You can view your old negative films content by setting the color effect to "Negative"
2. Snap your friend with the item he borrowed from you, then you're going to remember it the next time you're going through your photo gallery.
3. If your phone have a front Camera, then your phone can double as your Mirror.
4. With apps like Tiny Flashlight + LED, your phone can double as your Torch.
5. With apps like IP Webcam (Android), you can use your phone as a Security Camera or Surveillance Camera.
6. With Augumented reality games, you can use your phone as a Game-pad.
7. With Apps like Photomath (Android), you can solve Mathematics problems just by pointing your camera to the Question.
8. With apps like Heart beat rate (Android), You can measure your heart beat rate.
9. You can check your remote control dead batteries by pointing the camera at the top of the remote, and push a button on the remote while looking into the camera. If the batteries are dead or the button you pressed is faulty, you wouldn’t see any light emitted from the remote control.
10. With Apps like Smart Measure (Android), you can measure the distance between two points (e.g Someone's Height, a building's height e.t.c).
11. You can Detect Hidden cameras or CCTVs by switching off all the lights and draw the blinds. Switch on your phone camera. Make sure the flashlight is turned off. Turn round the room with the camera still on and check necessary areas in the room too... If you find a red dot, this signifies that a hidden web camera is installed somewhere inside that room. But if no red dot is found, the room is free from hidden cameras. This is not just applicable to rooms but any other dark place with surveillance camera.
12. With apps like SkyView (Android, iOS), point your phone camera up at the sky, and you can pick out stars, constellations and more without the aid of a telescope.
13. With OCR Apps like Google Goggles (Android) or TextGrabber (iOS), you can make printed books and documents editable.
14. With apps like RedLaser (Android, iOS, Windows Phone), Your phone can double as a Barcode and QR code scanner.
15. With apps like CamScanner (Android, iOS) and Scanbot (iOS), Your phone can double as your a Scanner(for receipts and other documents you come across).
16. With Google Translate (Android, iOS), you can translate a foreign language by point your camera to the text (e.g on a paper)
17. With apps like Google Goggles (Android), you can look at a product in person, and buy them online.
18. With Google Image search (Android, iOS, Windows Phone), you can just snap a friend and get some (useful) informations about him.
19. With apps like Magnify (Android), you can read tiny text or see small details by point your camera to them.