Huawei Ascend Mate — Need Help with "Shake To Lock"

You need to reboot into safe mode. When the phone if on, long press the power button, at the power menu keep paying on 'power off'. It'll reboot to safe mode, with only system apps running, from there you can uninstall any other app.

You need to hold the power off option for a while, it'll reboot into safe mode. Basically only pre-installed apps will open, go into settings/apps and uninstall the app that's causing the issue.

Well @Matas there in no need to unlock your device in order to reboot into the safe mode just holding the power+volume button for a while will take you to the safe mode !! One more thing why don't you try unlocking your device by using gmail account ??? Login into your gmail account i.e. the account which you're registered on your device, once logged in to the gmail account via PC goto the android device manager if the data connection on your device then on android device manager it will show you online and there is an option to unlock. once unlock go to the settings>security>device administrator and untick the buggy lock-screen application you are using on your device and then try uninstalling it I think It is going to get removed this time. let me know if this works for you !!

@matas have you tried using your gmail account to unlock your device !! I have mentioned two ways to do that ???

@matas Well, I think this might be because of two reason first is this is not the gmail account associated with your device and the second reason would be does you phone have an active wifi or data connection ??? If not them you can enable it by pressing the power button until you get a popup, from there enable your data connection. and then try doing the same !