As is pointed here the links for the locker app are broken
https://f-droid.org/forums/topic/locker-zygote-labs/
Does the f-droid servers hold a copy of the repo clone to make it available?
Edit: yes they do Locker | F-Droid - Free and Open Source Android App Repository
I installed this app today and it works perfectly. I wanted to propose some improvements
What does f-droid do in this situations? keep the app until it does not work in recent android versions?