Citizen Calculator is a precision-built calculator for iPhone that works exactly the way a real Citizen desktop calculator does — not a simplified phone calculator, but a complete professional tool you can rely on every day. # Real calculator logic Operations run left to right as you type. Press 2 + 3 x 4 and get 20, not 14 — exactly like a physical desk calculator. Constant equals lets you repeat the last operation by pressing = again. Every calculation is done in pure decimal math, so 0.1 + 0.2 gives 0.3, never a floating-point surprise. # Built-in GST calculator Add or remove GST at rates of 3%, 5%, 12%, 18%, and 28% with a single key. Switch rates instantly from the display chip without opening settings. Perfect for shopkeepers, accountants, freelancers, and anyone who works with Indian GST every day. # Five keypad layouts Each layout arrives with its own signature theme, so the calculator looks cohesive the moment you switch. # Choose the layout that matches how you work: - Citizen Pro: the standard desktop arrangement with all functions at hand - Citizen Desk: the classic desk layout with a tall equals key and separate function column - GST Pro: dedicated GST keys front and centre for tax-heavy workflows - Plus: a wide-format layout optimised for adding long columns of numbers # Twelve themes Citizen Classic, Desk Silver, Desk Carbon, Midnight Pro, Neon Night, Ocean Depth, Rose Quartz, Royal Gold, Retro LCD, Forest, Sunset Glass, and Minimal Light. Every theme applies a complete visual makeover — background, display, all key colours, shadows, and glow effects. # Professional calculator functions - Memory: M+, M-, MR, and MC. M+ and M- complete any pending operation before storing, just like a real Citizen. - Grand Total (GT): every equals result is automatically accumulated. Press GT to recall, press GT twice to clear. - Markup (MU): calculate the selling price for a target gross margin in one step. - Percent: completes with the pending operator — 200 + 10% gives 220. - Square Root: keeps the pending operator active, so 9 + sqrt 16 = gives 13. - Swipe left or right on the display to delete the last digit. - Long-press AC to reset everything including memory and grand total. # Physical key feel Every key press and release has a distinct haptic tick tuned to its role — light for numbers, firm for operators, rigid for equals. An optional key-click sound plays on every press. Keys animate with a press-and-bounce to feel like real physical switches. # Number formats Switch between international formatting (1,234,567) and Indian formatting (12,34,567) in settings. The display updates instantly. # Calculation history Every completed calculation is saved automatically. Tap any entry to load the result straight back to the display. History is preserved between app launches. # Privacy No account required. No analytics. No ads. All data — history, memory, total — is stored only on your device.