Do you consume tons of information but wish you retained more of it? Me too. Over the holidays I vibe-coded MasterFlasher, an Android app that turns content into AnkiDroid flashcards without interrupting what you’re doing.
The core insight: the moment you think “I should remember this” is rarely the moment you want to stop and make flashcards. MasterFlasher lets you silently share content from any app to an inbox, then batch-process it into cards later.
How it works:
Share from any app → content saves silently to a local inbox (no UI interruption)
URLs: in-app browser extracts article text via Readability.js
PDFs: text extracted on demand via pdf.js
Flashcard generation uses a multi-step Gemini pipeline: fact extraction → scoring → card generation
Review/edit cards, then push directly to AnkiDroid
Design choices:
Capacitor + Ionic + React, with Java plugins for the in-app browser and Room storage
BYOK: you provide your own Gemini API key (no server or proxy)
API keys stored on-device using Android KeyStore
Prompts are user-editable if you want to tweak output
Everything is local except the Gemini calls
For context: I’m not a software engineer. This is a hobby project to solve my own problem. I’ve since learned that LLM-generated flashcards aren’t an original idea, but I wanted something that fit my workflow: offline, share silently, process later, push straight to AnkiDroid. It also just seemed fun to build.
Free and open source. APK and source on GitHub: https://github.com/mortsnort/MasterFlasher
I don't have plans to monetize or go much further with this, but I'd welcome ideas for making it more useful for my own flashcard learning. Thanks for checking it out!
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