Tools you actually run.
Only where a calculation or simulation earns it — never decoration. Every one of these 16 tools runs in your browser; nothing you type is sent anywhere.
Prompt Builder
Fill the five parts → a ready-to-paste prompt.
Roleplay Builder
Scenario + counterpart + difficulty → a rehearsal prompt.
BATNA Calculator
Two walk-away numbers → does a deal exist, and where to open.
Compound Interest
The same money as savings and as debt, on one chart.
Model Picker
Describe the task → the right model tier, and why.
Order Book Simulator
Fire market orders at a live book → watch price move and slippage bite.
Portfolio Allocator
Horizon + risk → an illustrative asset split.
Net / Gross Salary
Gross + your own tax rates → net, and what a raise is really worth.
Chart Picker
What you're showing → the right chart, and when to use none.
Formula Explainer
Paste a spreadsheet formula → each function in plain English.
Fermi Trainer
Chain your assumptions → an order-of-magnitude estimate.
Terminal Sandbox
A safe shell over a fake filesystem — your first commands.
CV Checker
Paste your bullets → the weak patterns recruiters skip past.
Revision Scheduler
An exam date → a spaced-repetition schedule.
Timing Check
A five-point checklist → is now the moment?
Tone Checker
Paste a message → what makes it land wrong.