KeepCalc

KeepCalc - Calculator with Time & History

Automatically save all calculations. Simple, fast calculator with time calculation and percent
calculation features.

What is KeepCalc?

KeepCalc is a calculator app that automatically saves your calculation history. Handle complex
calculations with parentheses, calculate work hours, compute percentages - all in one app. Review your
calculation process and reuse past calculations effortlessly.

What's New in v1.2.0

[Time Calculation Feature]
• Automatically calculate time differences (e.g., 9:00-17:30 = 8:30)
• Automatic overnight calculation (e.g., 22:30-1:30 = 3:00)
• Perfect for work hours and overtime calculation
• Add and subtract multiple time ranges
• Supports both HMM format (130 = 1:30) and HHMM format (1430 = 14:30)

[Percent Calculation]
• Easy percent conversion (50% → 0.5)
• Swipe right on percent key for percent increase calculation ($100 + 20% = $120)
• Supports percent calculation inside parentheses
• Convenient for discount and tax calculations

[Lightning-Fast Performance]
• 95% faster backspace response (300ms → 16ms)
• 30% reduced memory usage
• Smooth and responsive operation
• 20% less battery consumption

[Enhanced Usability]
• Auto-scroll to latest calculation in history
• Swipe right on zero key for quick "00" input
• Improved cursor positioning for accurate editing
• Stable operation even with special characters

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Key Features

[Automatic History Saving]
All calculations are automatically saved. History persists even after closing the app, so you can
review and reuse past calculations. Tap history items to re-enter expressions instantly.

[Complex Calculations with Parentheses]
Supports nested parentheses for complex expressions. Swipe bracket button for individual parenthesis
input. Clear visualization of calculation order makes editing easy.

[Smart Input Assistance]
• Automatic thousands separator display
• Cursor movement for precise editing
• Select text and wrap with parentheses
• Double-tap for select all

[Convenient Gesture Operations]
• Zero key right swipe: Input "00"
• Percent key right swipe: Increase calculation
• Bracket key left/right swipe: Individual parenthesis
• Text field swipe: Cursor movement

[Clear Result Display]
Results shown in bubble format alongside expressions. Time calculations displayed in H:MM format. Large
numbers remain readable with automatic formatting.

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Perfect For

[Work Hours Calculation]
Calculate working hours from start and end times. Easy break time deduction. Convenient for overtime
tracking. Supports overnight shifts seamlessly.

[Shopping Calculations]
Percent discount calculations, tax-included prices, total of multiple items, bill splitting - perfect
for all shopping scenarios.

[Business Use]
Quote calculations, salary from hourly wage, expense aggregation, project time management - ideal for
professionals.

[Learning & Education]
Math practice, verify calculations, check answers, review with history - excellent for students and
educators.

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Simple and User-Friendly Design

Intuitive interface with large, easy-to-see buttons. Anyone can start using immediately. Accessibility
support included with screen reader compatibility.

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Privacy & Security

All calculation data stored locally on your device. No internet connection required - works completely
offline. No personal information collected. Safe and secure.

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Technical Specifications

• Built with Flutter for high performance
• 64-bit floating-point arithmetic
• Up to 10-digit precision
• Memory-efficient design

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Quality Assurance

Quality assured with 900+ automated tests. WCAG 2.1 AA compliant accessibility. Regular updates and bug
fixes. Continuous improvements based on user feedback.