Latest questions about "unhide"

I hid a contact. I know how to find hidden contacts. But when I follow the usual rules I cannot 'see' the contact at all.

I tried to unhide Gallery Lock using *password and dial, but it wasn't working. Please advise how to open unhided Gallery Lock?

Will I be able to unhide my pictures from the app lock? If yes, how can I do it? I have lost my pictures.

I attempted to access a website and a message came up saying that it was a threat and directed me to upgrade and make a purchase of Avast.