Beyota

Beyota is the calculator you'll actually want to look at. 56 built-in themes, and they change the shape of the keys too: raised tiles, borderless circles, hard-ruled grids, deep soft pillows, embossed keys, translucent glass. 17 are built on real photographs: an ocean afternoon, an anime night sky, Earth from space, a golden desert at sunset. 20 are dark. Others sweep gradients corner to corner, or glow in neon. Browse them in a gallery where every card is a miniature preview of the calculator in that theme, so you see exactly what you're getting. Search by name, sort by popularity or A-Z, filter by category. Tap one and the entire app re-skins instantly, with no restart and no Apply button, and it's still there the next time you open it. The theme goes everywhere, not just the keypad: the display, the menu, the settings screen, the unit converter and the date calculator. Underneath the style, it's a serious calculator. Standard, Scientific and Programmer modes, each with its own portrait and landscape keypad that switches as you rotate your phone. Arithmetic runs in exact decimal, so money-style sums stay precise. Scientific adds squares and cubes, roots, factorial, reciprocal, exponentials and logs, the full trig and hyperbolic set with inverses behind a 2nd key, a degrees/radians toggle, and dedicated π, e and random keys. Programmer shows HEX, DEC, OCT and BIN all at once, every row live on every keystroke. Tap one to type in that base. Four word sizes (QWORD, DWORD, WORD, BYTE) with true register-width masking, bitwise AND, OR, XOR and NOT, left and right shifts, and MOD. Digit keys grey themselves out to match the active base. A unit converter covers 38 units across length, weight, temperature, volume, area and speed, with its own keypad. A date calculator finds the difference between two dates, or adds and subtracts years, months and days from a date and tells you which weekday you land on. Every date field opens a calendar picker, and results update as you type; there's no equals button to hunt for. A history remembers your last 50 calculations and puts any of them back in the display with a tap. Beyota speaks 9 languages and switches between them instantly. It opens in your phone's language the first time you run it. And it works completely offline: no accounts, no ads, no telemetry, no analytics, no crash reporting. Beyota doesn't request internet access, and your settings and history stay on your device.