published by com.gumballtools

15 listings on this page, in order of arrival. Each one has its own page with README, repository facts and source links.

1. Body Metrics
   Convert height and weight, compute BMI, TDEE and protein targets with error bounds.
2. Check Digit Validator
   Validates IBAN/ISBN/EAN/Luhn checksums and finds the one wrong digit
3. Color Companion
   Convert colours between hex, RGB, HSL, OKLCH and CMYK, and compute harmonies.
4. Due Date
   Estimate a due date from LMP, conception, or ultrasound, with ACOG redating rules.
5. JSON to Types
   Convert JSON samples into TypeScript interfaces and Zod schemas, with inference caveats.
6. Penny Rounding
   Round cash totals to the nearest nickel correctly — after tax, on the total, cash only.
7. Project Gumball
   One MCP server exposing every tool in the Gumball portfolio.
8. Regex Explainer
   Explain a regex in plain English and detect catastrophic backtracking risk.
9. Sports Rules
   Work an offside call through IFAB Law 11 or NHL Rule 83, step by step.
10. Timezone Truth
    Convert times between IANA zones and detect skipped or ambiguous DST local times.
11. Words in Context
    Words-in-context vocabulary practice questions with distractor explanations.
12. Amortization Schedule
    Row-by-row loan amortization schedules: monthly or daily accrual, extra principal, PMI, biweekly.
13. Equation Steps
    Step-by-step solver for linear/quadratic equations in one variable, signs and ± always right.
14. ISO Week Number
    ISO 8601 week numbers: date to week, week to date, weeks-per-year.
15. Payload Validator
    Validate JSON, YAML, XML and CSV with exact line/column errors and silent-corruption warnings.