Know exactly when you can retire.

Coastline is a FIRE planning app for iPhone. Real projections, scenario modeling, and on-device AI — your financial data never leaves your phone.

Download on the App Store
Free to start. No account required.
Good evening, Tyler.
FI Progress
27%
$751K saved FI at 44
Portfolio Journey
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Desktop-class modeling.
In your pocket.

Professional-grade financial modeling, built natively for iPhone.

Monte Carlo

1,000 possible futures

Stochastic simulations show the real range of outcomes — not just the median. See your success probability across market conditions.

Scenarios

What if you retired 3 years early?

Create alternative futures that override specific assumptions. Compare them side by side with delta notation showing exactly what changes.

Tax Strategy

Keep more of what you've earned

Roth conversion ladders, ACA subsidy optimization, bracket analysis, and tax-aware withdrawal sequencing.

Stress Testing

Battle-tested plans

Seven black-swan scenarios — deep recession, stagflation, lost decade — tested against your specific numbers.

Withdrawals

Six strategies, one optimizer

Fixed, variable, guardrails, VPW, Vanguard Dynamic, and Guyton-Klinger. See which minimizes your lifetime tax bill.

On-Device AI

Summaries that understand your plan

Apple Foundation Models generate contextual narratives across 12 views — projection analysis, scenario comparisons, Time Machine year-by-year narration. Everything runs on your iPhone. No data sent anywhere.

Claude AI Advisor

Ask anything about your plan

Conversational FIRE strategy advice powered by Claude. Your questions go through an anonymized proxy — no names, no account numbers, no personal identifiers. Available with Pro.

No servers

Every calculation runs on your iPhone. Your financial data is stored locally and never transmitted.

No tracking

Zero analytics, zero telemetry, zero ad networks. We don't even know how many people use Coastline.

No account required

Download and start planning. No sign-up, no email, no password. Your data lives in your device's local database.

Your path starts here.

Free to start. Pro unlocks unlimited scenarios, AI advisor, and advanced tools.

Download on the App Store