App Overview

Anchor Sentry icon

Anchor Sentry

Michael Dieter Konz · Navigation

Anchor Sentry is an app to monitor the ship's position at anchor and inform the skipper when the anchor is dragging and thus the ship leaves the setup perimeter.

$3.99 · In-app purchases

PRICE
$3.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
4.0
4 ratings · Top 30%

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.

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What's included15 files

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

  • START_HERE
  • AGENTS
  • EVIDENCE
  • SPEC
  • BUILD_PLAN
  • DIFFERENTIATION
  • skills/
  • screens/
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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.

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> SELECT BUILD PLATFORM:

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

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

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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

Implement robust offline maps feature.

Assumption to check: Limited offline functionality for maps

Validate with people who use this workflow before building.

Hypothesis 2

Create a cohesive design system.

Assumption to check: Inconsistent user interface design

Validate with people who use this workflow before building.

Hypothesis 3

Add personalization features for users.

Assumption to check: Lack of user customization options

Validate with people who use this workflow before building.

Hypothesis 4

Clarify subscription options and benefits.

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

Anchor Sentry is an app to monitor the ship's position at anchor and inform the skipper when the anchor is dragging and thus the ship leaves the setup perimeter. Features: - Show current position on GoogleMaps map or Navionics map (To gain access to Navionics maps from this application, users with an active Navionics subscription in the Navionics Boating application must register with their Navionics credentials) - Distance circles to help finding a good anchor position - Drop anchor by tapping on map or by position or by bearing and distance - Can be used for anchoring with shore lines by watching the heading rather than the position - Tracks can be saves as GPX file for later processing - Option to set up prohibited zones which will trigger an alert when entered. These can be used indepent of the anchor state - Runs in the background even while other apps are used - Unique sync functionality which allows to pair two or more devices together to see the ships position even while out to shore for dinner - Barograph function included - Display real echo sounder data from a providing NMEA server - Optional compass overlay to help finding the bearing to the anchor - Option to show current position visible to friends and family on the Anchor Sentry website - Proximity alert between ships both using Anchor Sentry. To get warned when your neighbours anchor is dragging. - Automatic anchoring feature - Display maximum swinging circle - Save favorite anchoring places with pictures - Several setup options to customize your app

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Screenshots

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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
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Axios
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BUILD KIT DIFFICULTY
Advanced

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.