Numera
A fast, honest calculator for iPhone — with currency and unit conversion built in.
Free. No ads, no accounts, no analytics. iPhone only — it is designed for one hand and one screen size class, and I would rather do that well than do everything.
Brackets, after the fact
The bracket key wraps what you already typed. Realise halfway through that you needed parentheses, and you can add them retroactively instead of starting again.
History tape
Every result stays on a tape above the display. Press and hold a line to bring it back; tap it to copy.
Currency, offline
Rates come from the European Central Bank and are cached on device. It works on a plane; it tells you how old the rates are.
Unit conversion
Length, mass, area, volume, temperature, speed, time and data — 61 units with exact ratios, on the same keypad as your arithmetic.
