Sumthing
Calculations stay connected
Only for iPhone
£4.99
iPhone
A tape calculator where every calculation stays on a connected Slate. Edit anything and everything updates. Link results together. Keep your workings visible.
A tape calculator that remembers your workings.
Sumthing is a tape calculator built for people who think through problems, not just answers. Every calculation stays on a connected Slate — visible, editable, and linked. Change anything and the entire Slate updates automatically.
HOW IT WORKS
1. Enter a calculation using the keypad
2. Tap equals to commit it to the Slate
3. Tap any result to reuse it in a new calculation
4. Edit any number or operator — everything recalculates live
THE SLATE
• Every calculation stays on the Slate with its full expression
• Results link to each other — change one and dependent calculations update
• Colour-coded lines make it easy to follow your working
• Tap any result to branch a new calculation from it
UNIT CONVERSIONS
• Convert currency, length, weight, temperature, volume, and more
• Live exchange rates for 13 major currencies
• Conversions appear inline and stay linked to the Slate
• Quick presets: Basic, Extended, or All units
• Recent conversions for fast access
EDIT ANYTHING
• Tap any number or operator on the Slate to edit it in place
• All dependent calculations update immediately
• Cancel an edit to revert, or clear to remove a line
• No re-entering formulas — just fix and continue
FLEXIBLE DISPLAY
• Wrap mode shows full expressions across multiple lines
• Scroll mode lets you swipe through long formulas
• Configure decimal places from 0 to 10 with a live preview
• Long-press the display to copy the current result
DESIGNED FOR FOCUS
• Clean dark interface with a muted colour palette
• Smooth animations and subtle haptic feedback
• Full bracket support for order of operations
• Clear handling of negative values
Built for people who think with numbers.
Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Powertools
A new section for specialist tools and utilities, starting with Fib Finder.
Fib Finder
Work out the high and low anchor points of a Fibonacci retracement from any two known levels. Enter two fib levels and their prices, and Fib Finder solves for the full range — all standard levels plus extensions.
• Scroll wheel pickers for quick level selection
• Colour-coded input points with results listed high to low
• Show or hide extension levels with a toggle
• Enable Powertools from Settings to get started
The developer, Simon Belcher, 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.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Provider
- Simon Belcher
- Size
- 2.2 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Apexx Apps
