Goldbach's Conjecture Math vs (Open Source) Periodic Table

A little curiosity. A world of numbers. Explore Goldbach’s conjecture with your free prime-pair calculator, and take your curiosity further with a new Learn tab. YOUR CALCULATOR STAYS FREE Find one or up to 20 prime pairs, enter numbers up to 35 digits, keep history, save favorites and share results. No ads or app account required. 30 LESSONS, THREE PATHS Learn about primes, divisibility, factorization, modular arithmetic, Miller–Rabin, Euclid, twin primes, RSA and mathematical proof. Each lesson includes explanations, a worked example and a quiz with feedback. Lessons 1–5 are free. A DAILY SPARK Answer a free daily question, build a streak, bookmark lessons and track your progress. Goldbach Plus adds unlimited practice with instant explanations. EXPLORE THE LAB The interactive prime sieve up to 100 is free. Plus adds the Ulam spiral, prime-gap charts, Goldbach pair-count charts, CSV export and a factor explorer. Lab calculations use exact methods within their displayed small ranges. GOLDBACH PLUS Monthly and annual auto-renewing subscriptions unlock all 30 lessons, unlimited practice and the complete Lab. Both plans provide the same access. The existing calculator, history, favorites and sharing remain free. Prices and billing periods are shown before purchase. Payment is charged to your Apple Account. Subscriptions renew unless canceled at least 24 hours before the current period ends. Manage or cancel in App Store account settings. Restore active purchases in the app. PRIVATE BY DESIGN Lessons and math explorations work offline. Calculations and learning progress stay on this device. Progress does not sync between devices. Apple handles purchases. No tracking or advertising SDKs. Mathematical experiments do not prove the conjecture. Large-number factors may be probable primes rather than certified primes. Privacy & support: https://oanarinaldi.com/goldbachprivacy.html Terms: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

A clean, free periodic table for chemistry students, teachers, and curious people. Explore all 118 elements in an interactive table, then tap into detailed element cards with atomic, physical, discovery, and isotope data. Switch color modes to see trends across the table, search by name or symbol, compare properties, and use practical tools when homework or curiosity sends you down a chemistry rabbit hole. FEATURES Interactive Periodic Table Pinch, pan, zoom, and tap through the full periodic table with category colors and property heatmaps. Element Quiz Learn symbols, names, atomic numbers, and element families with quick 10-question rounds. Start with the first 20 elements and work up to all 118. Element Details See atomic mass, density, melting point, boiling point, electronegativity, radius, electron shells, discovery facts, isotopes, and more. Safety Data GHS hazard pictograms, signal words, and hazard statements for 77 elements, free. No PRO lock. Search and Lists Find elements quickly by name, symbol, or atomic number. Isotopes Browser Browse thousands of nuclides with half-life, decay, abundance, and nuclear data. Molar Mass Calculator Parse formulas with nested groups and hydrates, then see the element-by-element mass breakdown. Chemistry Tools Balance equations, review common reactions, inspect trends, and use reference tables for ions, solubility, constants, and organic series. Mini Academy and Dictionary Learn core chemistry ideas with compact lessons, glossary entries, and quick checks. No ads. No paywalls. No account required. 100% Open Source The complete source code is public - see it, audit it, or contribute at https://github.com/Open-Apps-Studio/periodic-table