KatKalk

KatKalk is a configurable position calculator designed for fast entry of many individual values.

Unlike a conventional calculator, KatKalk keeps every position visible. This makes calculations easy to follow, check and correct—even during fast-paced work.

KEY FEATURES

• Add, subtract, multiply, divide and calculate percentages
• Keep every entered position visible
• Add short notes to individual positions
• Save and reopen multiple sessions locally
• Copy or remove the latest position
• Choose from ready-made calculator profiles
• Customize the keypad, screen layout and visible controls
• Export sessions as readable HTML reports
• Print reports directly from a compatible browser
• Export and import KatKalk session files
• Use the calculator without an internet connection
• Follow shared sessions in read-only viewer mode

BUILT FOR PRACTICAL WORK

KatKalk is especially useful when many prices, products or other individual values must be entered quickly while the complete calculation remains traceable.

Choose a simple layout for everyday calculations or configure the keypad and display to match your own workflow.

LOCAL BY DEFAULT

Calculations, notes and saved sessions remain on your device. KatKalk’s core calculator works fully offline. Optional online features are clearly separated from local calculation.

OPTIONAL R77 KEY HELPER — ACCESSIBILITY API

KatKalk uses the Android AccessibilityService API for an optional key helper on the R77 with DumberOS. This lets the physical left softkey perform its saved calculator action while KatKalk is visible and hardware key capture is active.

The helper processes only physical menu-key events temporarily on your device. These events are not permanently stored or transmitted. Screen content and text from other apps are not read. No personal or sensitive data is collected or shared through this helper.

Activation is optional and requires your explicit in-app consent followed by enabling the service in Android accessibility settings. You can disable it at any time in those settings. Touch controls work without this helper.