Dangerous Pop up ??

Not always but often a pop up blocks everything on your phone - it says this app is slowing you phone and needs this upgrade. The only option is OK - which I will not push -so I have to shut down my phone and reboot. If the app needed updating it should go thru Apple like all other apps on my phone !! I am not sure if this is bogus but nothing else has ever locked my phone !

BubbaB1 about Video Poker ⋆ Deuces Wild, v1.0