[Plugin] ScreenLockPin: Simple PIN Lock for KOReader

Hey everyone!

I made a small plugin that adds a simple PIN lock screen to KOReader. To me, it's important that not just anyone can open my reader without privacy protection. The built-in multi-gesture unlock feature didn't suit me well. Nor did any plugin I checked out so far, so here we go…

I took the effort to have it somewhat polished, as I wanted to share this essential functionality with you guys. For now, the UI is very basic, as cosmetic features were less of a priority to me.

Let me know what you think :)

https://github.com/oleasteo/koreader-screenlockpin

Features (v2025.10-2)

🗽 Flexible PIN length — supports 4–8 digits
🚀 Lock on boot — secures your device on KOReader boot (configurable)
🔁 Lock on wakeup — secures your device after sleep (configurable)
🔒 Full-screen lock — hides content for privacy
⚡ Instant unlock — immediate response, no extra confirmation button
🚥 Rate Limiting — short delay after repeated failed attempts
⛅ Lightweight design — minimal overhead

A big thanks to all the KOReader devs. Proper plugin dev documentation would be great, sure. But for the most part, I managed to figure things out, and in the end, I was able to make it all work! Thank you for a great software that I enjoy to use on my kindle since about very recently.
:thanks: