Show & Tell: I built an offline-first PDF Scanner & Vault (optimized the bundle down to 20MB)

Hey everyone! 👋

I'm a solo student developer, and I recently launched Lihenium, an offline-first document toolkit for Android.

The Problem: I noticed that almost every popular PDF scanner app requires an internet connection just to crop an image or run OCR, and they are packed with unnecessary bloatware. For students and professionals in areas with spotty internet (or those who just value privacy), this is a nightmare.

The Solution: I engineered Lihenium so that all the core heavy-lifting—scanning, auto-edge detection, PDF merging, and OCR—runs completely locally on the device hardware.

The Latest Tech Update:

I just pushed a major architecture update today and wanted to share the milestone. I completely overhauled the Android App Bundle to support both 64-bit and the legacy 32-bit (`armeabi-v7a`) architectures.

The challenge was adding dual native libraries (including the Liftoff SDK) without bloating the app. After some serious optimization, I managed to unlock support for over 3,800+ legacy/budget devices while keeping the final user download size at just 20 MB.

Core Features:

* 📄 Fast document scanner with smart crop

* 🔒 Biometric "Secure Vault" for private files

* 🛠️ PDF editing, merging, and image-to-PDF tools

* 📴 100% Offline processing for maximum privacy

I'd love your feedback! If you have an Android device, I would be honored if you gave it a spin. Let me know how the UI feels and if you have any feature requests!

🔗 Play Store Link: https://play.google.com/store/apps/details?id=com.abhi.docu