App Overview

My Coast Fire Calculator icon

My Coast Fire Calculator

LetUsBake, LLC · Finance

Know when you can stop saving for retirement.

$0.99

PRICE
$0.99
No in-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
★ 5.0
3 ratings · Top 5%

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 included14 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 My Coast Fire Calculator: map the core Finance workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
            

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App evidence

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

Screenshots

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App Store description

Know when you can stop saving for retirement. Coast FIRE is the point where the money you've already invested will grow, on its own, into enough to retire on. You keep working to cover today's living costs, but you no longer need to save for retirement. From there, you're coasting. Coast FIRE Calculator shows you exactly where you stand. Enter a few numbers and see how much you need invested today, whether you're already there, and the age you'll get there if you keep contributing. YOUR COAST NUMBER, FRONT AND CENTER The big number at the top of the screen is your coast number: the amount you need invested today for growth alone to reach your retirement target. Next to it, a progress ring shows how much of it you've already funded. TURNS GREEN WHEN YOU CAN COAST While you're still building toward your coast number, the app is red and tells you the age you'll reach it at your current contribution. The moment your assets cover it, the whole app turns green: you can coast. SEE YOUR MONEY COMPOUND The Projection screen charts your portfolio year by year, all the way to retirement, against a dashed line marking your target. • Touch and drag across the chart to read your balance at any age • Milestone values show where your portfolio should be along the way • See your projected balance at retirement and your surplus or shortfall against your target • The projection assumes you contribute until you reach your coast number, then stop and let growth do the rest SLIDE IT OR TYPE IT Every input has a slider for quick what-ifs and a number you can tap to enter an exact value. Results update instantly as you change anything: • Your age and the age you want to retire • Current invested assets • Monthly contribution until you reach coast • Annual spending in retirement • Annual return rate • Withdrawal rate PLAN YOUR WAY Want to retire at 50? Planning cautiously with a lower return? Change your ages, savings, spending and assumptions to model early retirement, a traditional one, or anything in between. Lower the return rate or the withdrawal rate to see how a more conservative plan changes your coast number and target. PLAIN ENGLISH, NO JARGON The built-in Glossary explains the terms behind every number, in a sentence or two: • Coast FIRE • Coast number • Target • Annual return rate • Withdrawal rate HOW THE MATH WORKS • Target = annual retirement spending ÷ withdrawal rate. At a 4% withdrawal rate, that's the familiar "25 times your annual spending" rule. • Coast number = the amount that, growing at your return rate, reaches your target by your retirement age. • Both rates are real, already adjusted for inflation, so today's dollars and retirement dollars are directly comparable. WHO IT'S FOR • Anyone following FIRE (Financial Independence, Retire Early) • People wondering whether they've already saved enough for retirement • Savers deciding how much longer to keep contributing • Anyone who wants a clear, simple picture of long-term compound growth A clean, focused design with three tabs, Calculator, Projection and Glossary, keeps everything one tap away. Find your coast number today. --- Coast FIRE Calculator is an educational tool for estimates only and is not financial advice. Projections are based on the assumptions you enter; actual investment returns vary and are not guaranteed. Consider speaking with a qualified financial professional before making investment decisions. Terms of Use (EULA) : https://letuscake.com/coastfire.html Privacy Policy : https://letuscake.com/coastfire.html We’d Love Your Feedback Contact us at [email protected] . https://letuscake.com/coastfire.html

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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

Allow users to add custom expense categories.

Assumption to check: Limited customization for calculations

Validate with people who use this workflow before building.

Hypothesis 2

Add options to export results as PDF or CSV.

Assumption to check: No export functionality

Validate with people who use this workflow before building.

Hypothesis 3

Include a tutorial or tips for first-time users.

Assumption to check: Lack of user guidance

Validate with people who use this workflow before building.

Hypothesis 4

Implement a feature to track and manage recurring expenses.

Assumption to check: No recurring expenses feature

Validate with people who use this workflow before building.

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.

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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.