Digital Clock Lock is a widget which shows red digital clock on your lockscreen. It also changes the slide to unlock slider. You need to activate it through Winterboard.
Once activated you will notice that your default clock and Digital Clock are overlapping, to avoid this you need to install ‘LockScreen Clock Hide’ tweak from cydia.
This tweak will hide your default clock, which you can do by going to Settings after installing it. You will also notice that clock app icon is changed.
I’ve also tested it with/without cydgets it worked fine without any issues.
Only issue that I found is with cydialer cydget. If cydialer is activated it shows both default and Digital clock even after disabling it.
Digital Clock Lock is available on cydia under modmyi repo for free