[Q] Fire Lockscreen apk topic

I successfully downgraded to 3.5 with root and already "un-amazoned" my phone quite a bit (launcher, input, etc). However the lockscreen is giving me a hard time. I installed an alternative lockscreen app, but the old one keeps poping up.

Can anyone point me to the fire lockscreen apk, so i can replace it? (I suppose it is an apk and can simply be switched with root?)