Calculator with reverse screen vs Twin Calc

Calculator with a screen that can be displayed upside down to make it easier to read face-to-face

Twin Calc puts two independent calculators on one screen — a simple calculator app for anyone who has ever wished they had two. Compare two estimates. Split a bill two different ways. Convert on one side while you total on the other. Check last year's numbers against this year's. Open Twin Calc and calculators A and B are already there — no onboarding, no sign-up. Features - Calculator A and B stacked vertically (or side by side in landscape), each fully independent - Works just like the built-in iPhone calculator: + − × ÷, %, ±, backspace, and thousands separators - An expression line shows what you are calculating, so you never lose track - Drag the divider to resize the two calculators; double-tap to reset to half and half - Long-press a result to copy it; swipe left to delete one character - Haptic feedback (can be turned off) - History (tape) keeps your results automatically — tap to copy, or send a result back to A or B - Light and dark themes that follow your system setting - Both calculators and the split ratio are restored exactly as you left them Free - Two calculators, history, and reuse of your 3 most recent results - No ads PRO (one-time purchase) - Never retype a result again: send A's answer straight to B, or swap A and B in one tap - Bring back any past result from history - 3 extra themes: Midnight, Paper, and Mono PRO is a single one-time purchase. No subscription, no extra fees. Everything you calculate stays on your device and is never sent to a server. For iPhone (portrait and landscape).