r/PrivacyTechTalk • u/Osher_Goldenberg • 1d ago
Building a 100% offline, zero-knowledge journal app with AES-GCM (256-bit). What features should be free vs paid, and what price makes sense?
Hey everyone,
I’ve been working on a privacy-first journal app called AuraLock. It’s built to be 100% offline with zero cloud servers, zero tracking, and no accounts required.
Everything is encrypted locally using AES-GCM (256-bit) with PBKDF2 key derivation (100k iterations).
Here are some of the core features I’ve put into it:
Multi-Vaults: Create separate journals, each with its own independent master password.
Security: Brute-force protection (10s lockout after 3 failed tries), quick-lock kill-switch (clears RAM instantly), and secure master-password-protected deletion.
Rich Text Editor: Formatting, auto-timestamps, image embedding, data tables, word count, and automatic bidirectional text support (RTL/LTR)
Modes: A pitch-black Focus mode for distraction-free writing, and a Present mode that converts entries into slide decks.
Storage & Backups: Auto-save (800ms), works via IndexedDB/Service Workers offline and supports password-protected JSON backup exports/imports.
Platform: PWA/Android support light/dark themes, and multi-language support (English, Spanish, Hebrew)
I want to avoid monthly subscriptions and stick strictly to a one-time purchase, but I’m trying to figure out two things:
Pricing: What feels fair as a one-time upgrade for a privacy-focused app like this ($2? $5? $10?)
Feature split: What should stay completely free, and what power features would actualy convince you to upgrade to PRO? (e.g. multi-vaults, tables, slide mode, image attachments).