My phone was in my pocket for the whole afternoon until one of my friends borrowed it then gave it back again then asked why did I uninstalled my Camera though I always use it. I tried to open my Camera but it always says "App not installed" I tried to find it in Google play to see if Lenovo Cameras were there but they weren't. I also opened my gallery and the same thing happened, to see... My Phone Camera and Gallery are connected. What should I do? Searched online but nothing really helps...
I'd say your friend is making fun with you. If it's a system app (and there's usually a camera pre-installed that way), it cannot be uninstalled without root access (so you cannot have "accidentally uninstalled" those apps). He most likely disabled camera and gallery.
- Go to Settings → Apps
- Select the "All" tab (to list pre-installed apps as well)
- Scroll the list to find your camera app. Check whether it is marked "disabled".
- if so: tap that entry, hit the "Enable" button, done.
- Repeat previous step for your gallery app
You can try 3rd party app from store like "Google Camera".. https://play.google.com/store/apps/details?id=com.google.android.GoogleCamera&hl=en
Or if you are ROOTED.. then download .apk file of the Camera app and paste it into System folder and change its permission to Read Only. Then finally, Reboot.