Twelve fully offline categories
Twelve fully offline categories — Length, Mass, Temperature, Volume, Speed, Area, Time, Energy, Power, Pressure, Data, Angle. Plus Currency, with live rates from the Frankfurter API and a one-tap refresh.
Rosetta · Unit Converter
Rosetta
A converter that reads like a page.
Set in Fraunces with tabular numerals on warm parchment. Twelve unit categories plus live currency rates. Offline-first, ten favorites, no settings, no sign-in.
Coming to the App Store Coming to Google Play
Why Rosetta
Designed for the everyday.
Currency that works offline
Currency works offline once you’ve fetched rates at least once. The cache persists; the “as of” timestamp tells you how fresh it is. No signal? You’ll see a quiet line, not a wall of red.
A custom keypad set in Fraunces
A custom keypad set in Fraunces. Tap a number on either card to make it the active side; the other recomputes instantly. Both sides are first-class — you can convert in either direction with a single tap.
Star your ten favorites
Star any conversion to save it. Up to ten favorites live on the home screen, ordered by how often you use them. Long-press to remove.
Tap to copy, quietly
Tap the inactive number to copy it. A discreet “Copied” toast confirms. No menus, no popovers.
How it looks
A page set in Fraunces.
-
Home -
Converter -
Unit picker
Privacy, plainly
No accounts, no analytics, no ads, no in-app purchases, no notifications.
Your favorites live on this device only. The single network call Rosetta makes is the public Frankfurter currency rate fetch — everything else stays on your phone. Read the full privacy policy.
Questions
A short list, answered plainly.
- Does it work offline?
-
Yes, except live currency rates which require one online fetch (cached afterward).
- Why no settings?
-
There is nothing to configure that wouldn’t be a worse default than the one already chosen.
- Is my data tracked?
-
No analytics, no accounts, no ads. Nothing leaves the device except the Frankfurter currency rate fetch.