Fuusio – Applets & AI Agent

Marko Salmela

In-app purchases

About this app

Fuusio puts three things on your phone that usually live in separate apps: a catalogue of small utility tools, a runtime for self-contained web applets, and a personal database of data records. An embedded AI agent ties them together, and everything it makes stays on your device.


TOOLS – 50+ tools, all offline
Utility tools in ten categories: Construction, Date & Time, Design & Development, Finance, Health, Math, Science, Text, Travel & Navigation, and Units. All tools searchable, no network needed. Use AI agent to create new custom tools.


APPLETS – running in a safe sandbox
Applets are single-purpose, small web apps written in plain HTML, CSS and JavaScript. Fuusio ships a collection of pre-installed applets. Export, import and share new applets via Fuusio community server. Ask the agent build new ones - based on your needs.


PERSONAL DATABASE
Notes, todos, contacts and any other record type you define, organised into folders and searchable. Dates across your records feed the Upcoming card on Home, and overdue todos surface automatically. Generated applets can access database to utilise data items.


DASHBOARD
A stack of cards proving quick access to data and tools: today's date, location and sunrise/sunset, quick capture for notes and todos, urgent and upcoming items, recent tools and applets, clipboard capture, a food barcode scanner, and device status. Receive data from system clipboard and let AI agent store it to database. On the dashboard, there is the mighty Omnibar providing search across all features of the app and quick commands.


AI AGENT – bring your own API key
The AI agent can build applets, utility tools, or define a new kind of database record from a plain-language description. It can also read and write your files and records, and it asks for your approval before doing anything destructive.


The agent features require an API key from a language model provider, which you supply in Settings. Fuusio does not include a key or any AI service of its own. Supported providers at the moment: Anthropic, Google AI Gemini, OpenAI, and DeepSeek. Your key is stored encrypted on the device and sent only to the provider you chose. Usage is billed by that provider under their terms. Model lists are fetched live from each provider, so new models can be selected without an app update.


GAMES – because productivity needs a break
Staying productive means knowing when to stop. Fuusio includes eight classic games for the moments in between: 2048, 15-Puzzle, Falling Blocks, Lights Out, Minesweeper, Sudoku, Tap & Fly and Word Guess. All of them work offline, with no ads and no in-app purchases.


OFFLINE BY DESIGN
Tools, applets and your database work with no account and no backend. The only network calls Fuusio makes are the food barcode lookup (Open Food Facts) and the language model requests you enable with your own API key.


ALSO INCLUDED
A code editor with syntax highlighting for viewing CSS, HTML, JavaScript, and Markdown. In-app purchase unlocks editing functions in code editor.

Sharing, exporting, and importing applets and tools. Applets can be shared via Fuusio Community Server.

JavaScript REPL for evaluating JavaScript expressions.


Fuusio is for people who want a compact, but extensible toolbox with AI functions on their phone, want to keep their data local, and would like an AI agent that extends the app with new features.