Rechenbuch

Calculator, notebook, graphs

$0.49 · Designed for iPad. Not verified for macOS.

Solve equations for x, use a formula sheet with short explanations and convert amounts and units. Built for iPhone Duo. Rechenbuch is a calculator that takes the fold of iPhone Duo seriously. Folded, it works like a good desk calculator. The result appears only after “=”, and every calculation lands on a paper tape you can check, share as text or print as a PDF. A protective cover slides over the outer display and locks the keys in your pocket, while its window keeps showing the result. Unfolded, it becomes a book. Tabs with scientific functions sit on the left, the keypad on the right. Stand it up and the top half draws graphs. Lay it flat on the table and the left page turns into a notebook where variables and units calculate along. What’s inside: • Paper tape with step-by-step working, export as text or PDF • Scientific functions, degrees or radians always visible • Equation solver, also for other variables. Linear and quadratic equations come out exact, with roots or fractions • Graphs with sliders, zeros, maxima, minima and intersections • School formula sheet, each formula with a short explanation. Leave one field empty and Rechenbuch works it out • Converter for amounts and units, from teaspoons to kilowatt-hours • Notebook with variables and units: width = 4.2 m, depth = 3.1 m, area = width × depth • Statistics, physical constants, bit operations from 8 to 64 bits • Sales tax in one tap, rounding you choose and can see • Exam mode that locks graphs, the equation solver, variables and the notebook • Widget with your last result • Left-handed mode, large text, VoiceOver, English and German Every other iPhone and iPad gets the same features, iPad with book view and desk mode. No ads, no account, no data collection. Your calculations stay on your device.

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The developer, Mobile Box - App Consulting UG (haftungsbeschraenkt), indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    Mobile Box - App Consulting UG (haftungsbeschraenkt)
    Size
    4.8 MB
    Category
    Utilities
    Compatibility
    Requires iOS 27.1 or later.
    • iPhone
      Requires iOS 27.1 or later.
    • iPad
      Requires iPadOS 27.1 or later.
    • Mac
      Requires macOS 27.2 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 27.2 or later.
    Languages
    English and German
    Age Rating
    4+
    Copyright
    © 2026 MOBILE BOX - App Consulting UG (haftungsbeschränkt)
  • Privacy Policy

    • Supports

    • Family Sharing

      Up to six family members can use this app with Family Sharing enabled.

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