Actually not a bad lock screen app  but once installed  you must remove AcDisplay as an administrator before you can uninstall it. It took me a little while to figure this out  until I did  it was like Zombie apocalypse  the thing just kept reappearing. Seems like something nefarious was going on  no other lock screen requires administrator privileges. I might try the app again and see if it will function if I don't give it admin rights  but this thing scares me a bit.