I noticed there are a lock of security apps in the playstore that somehow can "lock" apps on a users device so they can not run them - for example, to prevent kids from use certain apps.
How are these apps able to lock other apps on the device without the device being "rooted"?
An app's launcher intent can be disabled.
Once that is done there is no way to launch the app - and the app will no longer appear in the device's launcher app.