There is a technical term, when you have turned your phone on and off and on and off and on and FINALLY it works but the only apps which function are the factory settings ones so all the useful stuff like kniiting gauges and the colour matching program and the whatsthatwordinfrenchandjapanese app just sit there laughing at you.
It's called Bricked.
And my phone has just done it.
And I expect it could be cured by syncing with my MacBook but since that is 500 miles to the north at the moment it's not a lot of use.
More time for knitting!