Odumak Calculator

Odumak Calculator

Odumak Calculator (HutCalc) is an Android calculator app developed by BS Planet. Six modes share one calculation history and memory: basic, scientific, programmer, conversion, everyday and RPN. It is free and has no in-app purchases.

Modes

• Basic: operator precedence done correctly (1+2×3=7), a three-line display that keeps long expressions visible
• Scientific: trigonometry, logarithms, exponentials, factorials, degree/radian switching, inverse functions on the 2nd key
• Programmer: hex/decimal/octal/binary shown and switched instantly, bit operations, 32-bit wraparound arithmetic
• Conversion: twelve categories including length, weight, temperature, data and currency (exchange rates are a fixed snapshot built into the app, not live rates)
• Everyday: tip, VAT (including reverse calculation from tax-inclusive prices), discounts, loans, compound interest, BMI, dates, percent change, cryptocurrency (total and net proceeds from quantity, unit price and fee)
• RPN: reverse Polish notation with a visible stack

Calculation rules

Display is limited to 15 significant digits, so digits beyond what double-precision arithmetic can guarantee are never shown. Monetary calculations such as loan payments and compound interest use decimal-precision arithmetic instead of binary floating point, avoiding errors of the 0.1+0.2=0.30000000000000004 kind. Conversion factors follow the BIPM SI definitions, the 1959 international yard and pound agreement, ITS-90 for temperature, CODATA 2022 for physical constants and IEC 80000-13 for data units (1 KiB = 1024 bytes), with sources cited inside the app. BMI classification applies the international standard (overweight at 25) or the Asia-Pacific standard (overweight at 23) according to the device region. Programmer mode applies the same 32-bit rules to both bit operations and arithmetic.

Input and interface

Handwriting input is a labs feature; once the recognition model has been downloaded, recognition runs on the device. Calculation history, memory and a tape are included, and history can be shared as text. The percent values used for tips, discounts and VAT are user-defined and persist. There is a home screen widget and a quick settings tile, and the widget can show dots instead of the result. Physical keyboards work, and numbers pasted with thousands separators are accepted. A pressed key sinks as its shadow contracts, and vibration fires at the moment of contact with a strength that depends on the key type. Vibration has three strengths and five feels, and can be turned off. On foldables and tablets the calculator and history are laid out in two columns. There are twenty design themes, each with its own key-cap shape, texture and color and its own grain, sheen and bezel depth for the body and the display. Brightness is dark or light and can follow the system setting. Nine interface languages are available: Korean, English, Japanese, Chinese (Simplified and Traditional), German, Spanish, French and Portuguese. Every key has an accessibility label, touch targets are at least 48dp, and the reduce-motion setting is respected.

Advertising and data handling

No advertising plays by itself or interrupts use. Super Boost in Settings makes keys spring up when pressed and plays a screen effect when a result appears; it does not change any result. A rewarded video plays only when the user chooses Unlock Super Boost with an ad in Settings, and watching it to the end switches Super Boost on for 24 hours. The nineteen design themes other than Classic can be chosen only while Super Boost is on, and a chosen theme stays after Super Boost ends. Every calculation remains available without Super Boost. The app asks once on the 5th, 13th, 26th, 47th and 81st launch whether to watch an ad for Super Boost and never after that, and watching one to the end pushes the next ask further away. No video is available yet in the European Economic Area and the United Kingdom. While an ad plays, the advertising identifier, IP address and device information are sent to Google. Network access is limited to downloading the handwriting recognition model and receiving an ad. Calculations, history and settings are stored only on the device; there is no account and no login. The developer is BS Planet and the contact address is support@bsplanet.app.