# Sumthing — Calculations stay connected

> Calculations stay connected (iPhone/iPad app by Simon Belcher.)

- Source: https://appshunter.io/ios/app/sumthing/id6758316109 (this page in markdown: same URL + `.md`)
- Developer: [Simon Belcher](https://appshunter.io/developer/1863433356)
- Category: Utilities, Productivity
- Price: $4.99
- Age rating: 4+
- Requires: iOS 17.0 · 2 MB
- Languages: English
- Released: 2026-02-03
- Data updated: 2026-05-18
- User reviews in markdown: https://appshunter.io/ios/app/sumthing/id6758316109/reviews.md

## What is Sumthing?

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/


## Version history (last 5 releases)

### 1.3.0 — 2026-04-17

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

### 1.2.1 — 2026-02-11

Unit Conversions

Convert between units right in your calculations. Tap the convert button to transform any number:

• Currency — Live exchange rates for 13 major currencies, loaded on app launch
• Length — Metric and imperial, from millimetres to miles
• Weight — Grams to tonnes, ounces to stones
• Temperature — Celsius, Fahrenheit, and Kelvin
• Volume — Cups, litres, gallons, and more
• Area, Speed, Pressure, Data Storage
• Lab Units — Medical conversions for glucose, cholesterol, hormones

Conversions appear inline on the Slate and update automatically when linked values change.

Also in this update:
• Improved haptic feedback throughout
• Tap any result while building to finalise and branch
• Better error messages (e.g. "÷ by 0")
• Improved mode strip styling
• Bug fixes and polish

### 1.2.0 — 2026-02-08

Unit Conversions

Convert between units right in your calculations. Tap the convert button to transform any number:

• Currency — Live exchange rates for 13 major currencies
• Length — Metric and imperial, from millimetres to miles
• Weight — Grams to tonnes, ounces to stones
• Temperature — Celsius, Fahrenheit, and Kelvin
• Volume — Cups, litres, gallons, and more
• Area, Speed, Pressure, Data Storage
• Lab Units — Medical conversions for glucose, cholesterol, hormones

Conversions appear inline on the slate and update automatically when linked values change.

Also in this update:
• Improved haptic feedback throughout
• Tap any result while building to finalize and branch
• Better error messages (e.g. "÷ by 0")
• Bug fixes and polish

### 1.1.6 — 2026-02-05

• Clearer error messages when calculations fail                                                                                                               
• Fixed decimal display while typing                                                                                                                          
• Improved editing experience

### 1.1.5 — 2026-02-04

• New mode indicator shows your current action
• Smarter display of small decimals
• Improved scroll behaviour
• Bug fixes and polish

## More apps by Simon Belcher

- [GetReel](https://appshunter.io/ios/app/getreel/id6757408903)

All apps by Simon Belcher: https://appshunter.io/developer/1863433356

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-05-18.*