App Overview

CoordCalc icon

CoordCalc

Justin Time · Navigation

A coordinate utility app that calculates the distance and initial/final bearings between two points on Earth specified either manually by latitude and longitude or automatically using the built-in map

$2.99 · In-app purchases

PRICE
$2.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
3.0
4 ratings · Below Average

Evidence scope: No current overall US chart position is available. Category-chart positions shown in discovery are a separate scope. Revenue is a directional model estimate, not verified earnings.

Build your own version

Build Kit

Make this idea yours

A product spec, screen plans, and build steps for your coding agent.

First kit free with a verified email

Add to a Remix

Combine features and design from your favorite apps.

Kit ready. Verify your email to download it.

What's included14 files

A product spec, phased build plan, differentiation notes, and screen references.

  • START_HERE
  • AGENTS
  • EVIDENCE
  • SPEC
  • BUILD_PLAN
  • DIFFERENTIATION
  • skills/
  • screens/
Preview a sample Build Kit No email needed

Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.

Feature spec

Goal: Send a clear invoice after finishing a job.

  • Add a client, line items, a due date, and payment instructions.
  • Preview the total before exporting a PDF.
  • Keep an editable draft if export fails.

Screen plan

Invoice editor: Client at the top, editable line items in the middle, total and preview action at the bottom.

States: Empty draft, validation errors beside each field, exporting, and a retry action that preserves the draft.

Differentiate and validate

Hypothesis: Contractors need faster repeat invoices more than more templates.

First experiment: Test duplicating a previous job with five contractors. Watch where they hesitate before expanding the feature set.

The full kit adds a phased build plan, evidence notes, tool prompts, and implementation guidance. It is a plan for your coding agent, not a finished app.

Usage: Mechanics are fair game; never reuse the original name, branding, assets, or verbatim copy.

JavaScript is required to complete mailbox verification.

Free quick prompt For a smaller starting point

Quick prompt

> SELECT BUILD PLATFORM:

Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.

// RORK SYSTEM PROMPT
Rork plan preview for CoordCalc: map the core Navigation workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
            

Preview ready. Verify your email to reveal and copy the full prompt.

JavaScript is required to complete mailbox verification. Return to this prompt preview.

Continue in Rork copies the full prompt to your clipboard first, then opens Rork in a new tab.

Continue in Rork >

Affiliate link: CloneChart may earn a commission at no extra cost

Opportunities

AI-GENERATED OPPORTUNITY HYPOTHESES

These are generated suggestions, not verified review quotations. Check current App Store reviews and speak with users before treating a possible gap as a requirement.

Hypothesis 1

Expand to include more formats and conversions.

Assumption to check: Limited coordinate formats supported.

Validate with people who use this workflow before building.

Hypothesis 2

Focus on simplifying the user interface and enhancing user experience.

Assumption to check: 3.0/5 rating suggests usability issues.

Validate with people who use this workflow before building.

Hypothesis 3

Implement offline capabilities for conversions and history access.

Assumption to check: No offline functionality.

Validate with people who use this workflow before building.

Hypothesis 4

Clarify purchasing options and improve visibility of conversion limits.

Assumption to check: In-app purchase confusion.

Validate with people who use this workflow before building.

App evidence

Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.

App Store description

A coordinate utility app that calculates the distance and initial/final bearings between two points on Earth specified either manually by latitude and longitude or automatically using the built-in map. It can also calculate a final position given an initial position, distance, and bearing. ################################ Limited time sale, get it now before the price increase to $4.99 ################################ The final distance can be calculated in miles, kilometers, nautical miles, yards, meters, or feet. Coordinates can be specified in and converted to and from decimal degrees, decimal minutes or decimal seconds. Bearing is returned in degrees true. Uses WGS84 for improved great circle distance calculation accuracy. NOTES: Coordinate messages can only be sent to other CoordCalc users and are available only within the app. Additional Features: -Can use internal GPS to find the lat/lon coordinates of your current location -Can use and drag the points around on the built-in map and get distance/bearing updates continuously. -Shows starting and ending positions on a map -Saves the previous set of starting and ending positions -Maps can display satellite imagery, and labeled roads, highways, cities, oceans, etc. -Can send coordinate messages with short notes to other CoordCalc users. - Built-in HD version for iPad Example use cases: -Navigation tool for aircraft, boats, etc. -Measure walking distance -Finding your exact position in order to mark points of interest/landmarks or meeting places. -Visualize and edit starting and ending locations using the map feature. -Calculate the size of various landmarks if they are visible via satellite. -Save the position of your parked car -Convert coordinates between different formats Checkout the revamped website and video at: www.justintimeapps.com iOS 4.0 Tested A video demo of how to move the pins is located here: http://www.justintimeapps.com/ts.html This pin jumping issue has been fixed in iOS 4.0, but for iOS 3.0 users, the difficulty of this depends alot on your screen protector. If the protector has a rough surface and causes your finger to jump around, the pin will be dropped often. You will get a better response if you move your finger slowly. Although, you should still be able to move a pin from the top to the bottom of the screen within 2 seconds without losing track. In iOS 4.0, this is not an issue.

Written user reviews are not shown here. Check current App Store reviews >

Screenshots

< Scroll to see more >

Build scope

Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.

Define the first version

Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.

Set boundaries

Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.

Check the hard parts

Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.

SUGGESTED BUILD STACK
React Native
Expo
react-navigation
react-native-maps
@react-native-async-storage/async-storage
TypeScript
BUILD KIT DIFFICULTY
Starter

From the Build Kit assessment.

A reliable timeline needs an agreed scope and a technical check. Ask your agent to estimate the phases in BUILD_PLAN.md after that review.