Tools
Tools are the simplest Reactive apps: a percentage calculator, VAT breakdown, days between two dates, a group expense splitter. They open in one click and do their job right away — but underneath they are ordinary Reactive documents: save them to your library, look inside to learn the syntax, and turn them, with the AI assistant, into the calculator you actually need.
The ready-made tools
Everyday utilities, from discount math to a password generator: no sign-up, no data leaving the browser.
How they work
Open and compute
Each tool opens in one click and works right away, on your phone too: no account, no install, no ads watching you.
Keep them with you
Save it to your library and it stays there, available offline too: a tool is a simple file — export it, share it with a link.
Make them yours
Add the VAT rate you always use, an extra field, a history of your calculations: describe it to the AI assistant and the generic tool becomes yours.
Private by design, whatever the context
Apps run and store data only in the browser; the AI works on the device too; collaboration, if you turn it on, is encrypted end to end. And every app remains a simple text file: readable, exportable, yours.
Curious how they're made? Start from the step-by-step guide or browse the full catalog.
Ready to try?
It opens and runs right in your browser: nothing to install, no sign-up, and the data stays yours.
Build your app