[Plugin] ScreenLockPin: Simple PIN Lock for KOReader

[oleasteo]

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.

[oleasteo]

The recent v2025.10-3 and v2025.11 releases have improved the plugin further:

🎴 Ontop the wallpaper — less screen estate to refresh, keep showing (most of) the wallpaper
🗽 Increased PIN flexibility — support 3–12 digits
↔️ Size and position — allows for single-handed input position
📃 Contact notes — for people to know how to return a lost device

A great time to update if you're already using this plugin ✨

I can't call it a simple plugin anymore, though 😅 It's fast and sophisticated. It finally (subjectively) exceeds any OEM PIN lock that I know.
An essential plugin to any koreader main-looped device, IMO.

Also, I now own an old kobo device to test the plugin on. So far, it works flawlessly.

[Clebbel]

Hi, I'm just wondering how easy/difficult it would be to add a time feature to this pin lock?

For example I am trying to have a lock that kicks my kids off at bedtime and then unlocks in the morning. I have another plugin that works on Jailbroken Kindle running KOreader, but it doesn't seem to operate the same on the Kobo.

thanks

[oleasteo]

Originally Posted by Clebbel

Hi, I'm just wondering how easy/difficult it would be to add a time feature to this pin lock?

For example I am trying to have a lock that kicks my kids off at bedtime and then unlocks in the morning. I have another plugin that works on Jailbroken Kindle running KOreader, but it doesn't seem to operate the same on the Kobo.

thanks

I would outline it like this:

1. This plugin could expose actions to fully disable (and immediately unlock) / enable (and immediately lock).
2. Another plugin could be made to trigger any actions on configured times.

The first step would be pretty easy for me to do. Currently, the "Lock screen" action exists.

For the extra plugin, I think koreader-break-timer is a great place to start, as it has a "bed time" feature. For a quick solution, one would probably just need to replace the message box with dispatching the actions of our plugin instead and remove all the unrelated code.

So, altogether, I don't think it's that big of a task to get to a working solution.
Are you somewhat familiar with writing code yourself? I could provide the necessary actions, but for the other task, that's out of my priorities right now.