Amarok

Amarok is an Android utility for concealing selected files and installed applications from ordinary view. Its stated purpose is to hide private files and apps in a single action, so the working pattern is a list of chosen items plus a toggle that removes them from where they would normally appear — the launcher for applications, and the visible file listing for documents and media. It is aimed at a device shared with family members, colleagues or a repair technician, where the goal is to keep certain items out of casual sight.

The application is published by deltazefiro under Apache-2.0, a permissive licence that allows reuse in both open and proprietary projects and includes an explicit patent grant. Being Android-only, it is not usable for hiding material on a desktop system.

Note the scope implied by the description: it addresses visibility, not encryption or access control, and the record here does not describe what happens to hidden items during a backup, a system update, or an inspection with a different file manager. Those behaviours are worth confirming in the project's own documentation.