The Change Languages app, let you activate all supported Samsung languages and keyboard inputs, This application works without any intervention from you, but After 4.2 new Jelly Bean, The protection level definition of CHANGE_CONFIGURATION has been changed and you have to allow the CHANGE_CONFIGURATION manually, If you know how to use adb command of android development tools , you can download it and grant the permission manually ,to this app by connecting your smartphone to your laptop with a cable, using this command through your laptop :
adb shell pm grant com.jkdevandroid.changelanguages android.permission.CHANGE_CONFIGURATION
If you have SuperUser privilege on your device. Change Languages could get the permission automatically. Starting from Android 7 Nougat, the application will request for a new permission that is required to write system settings, There are some devices variants (US,Chinese) that remove completely all unused languages, unfortunately there is no much thing we can do in this case.
Please contact us if you need any help.
In Change Languages 2.0.0We will always do our best to provide you with a safe and useful application.