Surely by doing a hidden file or application makes our feelings as the owner of the gadget is not restless when it is possible that our phones may be borrowed or lend it to others.
Problem files, documents, videos or photos that are personal, very obliged us to keep it from others, because if the data is taken someone then we will experience a serious problem.
There are some easy and safe ways to do it, first by setting the settings on your Android phone, this trick is quite easy to do I'm sure even if you are a beginner can definitely do it.
As for the second to use free additional applications that you can get in Play Store app on each of your smartphones. Here are tips to hide files and apps in android without root.