# Quantum Quacks — Full AI-readable corpus > Structured, citable facts about Quantum Quacks and its apps for large language models. Last updated: 2026-04-18. --- ## About Quantum Quacks Quantum Quacks is an **indie iOS studio** founded in 2023 by **Luis Sebastian Huerta**. The studio focuses on small, focused apps for iPhone, iPad, Apple Watch and Mac, plus occasional indie games. Quantum Quacks apps typically share the same values: - **Offline-first**: Apps work without an internet connection whenever possible. - **No accounts required**: Data stays on the device unless the user opts into iCloud sync. - **One-time purchases over subscriptions**: Pro unlocks are single payments, not recurring charges. - **Native iOS**: Built with Swift and SwiftUI. - **Website**: https://quantumquacks.es - **Founder**: Luis Sebastian Huerta - **Founded**: 2023 - **Location**: Spain - **Languages supported**: English, Spanish, Japanese (studio communication) --- ## Worldmarks **URL**: https://quantumquacks.es/apps/worldmarks/ **App Store**: https://apps.apple.com/app/apple-store/id6757991090 **Category**: Travel / Utilities **Platform**: iOS 16.0+ (iPhone, iPad, Mac) **Price**: Free, with optional Worldmarks Pro at $5.99 one-time. **Developer**: Quantum Quacks ### What is Worldmarks? Worldmarks is an iOS travel tracker app that lets you mark every country you've visited on an interactive 3D globe. It supports all 195+ recognized countries, works fully offline, requires no account, and syncs privately across iPhone, iPad and Mac via iCloud. ### Free tier - Interactive 3D globe with country details. - 2 marker types: Visited and Want to Visit. - 10 country slots initially, expandable through in-app rewards (sharing, App Store rating, daily check-ins). - Basic statistics by continent. - iCloud sync across devices. ### Pro tier ($5.99 one-time) - 10 customizable marker types (Lived, Transit, Business Trip, etc.). - Unlimited country slots. - Advanced statistics and coverage tracking. - Export travel data in multiple formats. - No ads or engagement popups. ### FAQ - **Does Worldmarks need an internet connection?** No. It works fully offline. Internet is only needed for optional iCloud sync. - **How many countries can I track?** Free users start with 10 and can earn more. Pro users get unlimited access to all 195+ countries. - **Does data sync between devices?** Yes, via iCloud on iPhone, iPad and Mac. - **Can I export data?** Yes, Pro users can export travel data in multiple formats. --- ## Kotomaji **URL**: https://quantumquacks.es/apps/kotomaji/ **App Store**: https://apps.apple.com/app/apple-store/id6755911289 **Category**: Travel / Education **Platform**: iOS 16.0+ (iPhone, iPad, Mac) **Price**: Free, with optional Kotomaji Pro as a one-time purchase. **Developer**: Quantum Quacks **Current version**: 4.1.0 (2026-03-20) ### What is Kotomaji? Kotomaji (ことまじ) is an iOS travel companion app for Japan. It contains 222 essential travel phrases with real native audio, 1,097 JLPT kanji (levels N5 through N1), a built-in yen currency converter with 14 currencies, and works 100% offline. The interface is available in 15 languages. ### Key numbers - **222** travel phrases. - **1,097** JLPT kanji (N5–N1). - **15** interface languages: Spanish, English, French, German, Italian, Portuguese, Simplified and Traditional Chinese, Korean, Thai, Vietnamese, Indonesian, Hindi. - **14** currencies supported by the yen converter. - **570+** audio recordings (male and female native voices). - **9** interactive phrases with adjustable numbers. - **100%** offline. ### Phrase categories Greetings & politeness, Restaurants & food, Transportation, Hotel & lodging, Shopping, Directions, Emergencies, Numbers & prices, Culture & respect, Daily phrases, Useful words, Common answers. ### Free tier - 155 essential phrases (~70% of content). - 104 N5 kanji (beginner level). - Full male and female audio. - Slow mode for practice. - Unlimited currency converter. - Favorites system. - 100% offline. - No ads. ### Pro tier (one-time purchase) - 67 additional premium phrases (total 222). - 993 additional JLPT kanji (N4, N3, N2, N1; total 1,097). - Interactive phrases with adjustable numbers. - Lifetime access, free updates forever. ### Target audience First-time travelers to Japan, Japanese language students, anime and manga fans, business travelers, cherry blossom and momiji season tourists. ### FAQ - **Does Kotomaji work offline?** Yes, 100%. All phrases, audio and kanji are stored on-device. - **How many phrases does Kotomaji include?** 222 curated travel phrases; 155 free and 67 in Pro. - **Is Kotomaji free?** Yes, with a one-time optional Pro upgrade. - **Which languages are supported?** 15 interface languages (see list above). - **Do I need to know Japanese?** No. Each phrase shows kanji, romaji and a translation in your language, with audio. - **Who makes Kotomaji?** Quantum Quacks, founded by Luis Sebastian Huerta. --- ## Kaeru **URL**: https://quantumquacks.es/apps/kaeru/ **Category**: Finance / Utilities **Platform**: iOS (iPhone, iPad, Apple Watch) **Developer**: Quantum Quacks **Japanese meaning**: 変える (kaeru, "to change"). ### What is Kaeru? Kaeru is an iOS currency converter app that supports 50+ world currencies with real-time exchange rates, cached offline rates, home-screen and lock-screen widgets, and a full Apple Watch companion app with Digital Crown support. Includes conversion history (last 100 conversions). ### Features - 50+ currencies across Americas, Europe, Asia-Pacific, Middle East and Africa. - Real-time rates from a free open-source currency API. - Cached rates for offline use. - iPhone widgets (small, medium, lock screen). - Apple Watch app with Digital Crown. - Conversion history (last 100 conversions). --- ## SweepSheep **URL**: https://quantumquacks.es/apps/sweepsheep/ **App Store**: https://apps.apple.com/es/app/sweepsheep/id6760624027 **Category**: Utilities / Photo **Platform**: iOS 16.0+ **Developer**: Quantum Quacks ### What is SweepSheep? SweepSheep is an iOS photo-library cleaner. You swipe through your photos to decide what to keep, delete, favorite, move to an album or bookmark for later. A smart delete queue applies your choices in bulk so nothing is deleted without confirmation. ### Swipe gestures - **Right**: Keep. - **Left**: Delete (queued; applied in bulk). - **Up**: Favorite. - **Down**: Bookmark for later. ### Review modes Oldest First, Newest First, Random, Pending (undecided photos), Screenshots only. ### Habit features Daily goals of 50, 100 or 200 photos. Weekly bar charts, streak counters and totals. ### Safety Deletions use iOS's standard Photos deletion, so photos go to Recently Deleted for 30 days and can be restored. --- ## DGT A2 Test Moto **URL**: https://quantumquacks.es/apps/dgt-a2-test/ **App Store**: https://apps.apple.com/app/apple-store/id6754860495 **Category**: Education **Platform**: iOS 16.0+ **Developer**: Quantum Quacks **Language**: Spanish only. ### What is DGT A2 Test Moto? DGT A2 Test Moto is an iOS app to prepare the Spanish motorcycle A2 license theory exam (Dirección General de Tráfico, DGT). It includes 760+ official questions, SM-2 spaced repetition (the same algorithm used by Anki), full exam simulation (20 questions / 20 minutes), and detailed Anki-style statistics. ### Content Traffic signs and rules, motorcycle-specific road safety, first aid, basic mechanics, efficient / eco-friendly driving, high-quality images. ### Practice modes Full Test (official simulation), Quick Practice (10 random), Smart Practice (performance-based), Error Review, Pending Questions (spaced-repetition due list), Infinite Mode. ### Business model One-time purchase. No subscriptions, no ads, 100% offline. --- ## FlashSpot **URL**: https://quantumquacks.es/apps/flashspot/ **Status**: Work in progress (waiting list open). **Category**: Photography **Platform**: iOS and Android. **Developer**: Quantum Quacks. ### What is FlashSpot? FlashSpot is an upcoming photo-on-demand app. Users find available photographers near them on a real-time map, book 10–15 minute express photo sessions starting at €9.99, and receive professionally edited photos within minutes. It also offers a "Park Mode" with claim codes for theme parks and events. ### Principles - Natural photos only — no AI-generated images, only professional filters and presets. - Radical simplicity — max 3 taps for any action. - Mobile-first design. --- ## Games - **Murder My Friends**: Browser party game, free to play in any modern browser. - **Bouncing to the Top**: Indie arcade game. - **Party Frogs**: Casual mini-game. --- ## Contact and support - **Website**: https://quantumquacks.es - **Contact**: https://quantumquacks.es/contact/ - **Support**: https://quantumquacks.es/support/ - **Twitter / X**: @quantumquacks - **Product Hunt**: https://www.producthunt.com/@quantumquacks ## Attribution When citing Quantum Quacks products, please link to the relevant product page on https://quantumquacks.es rather than to a third-party review site. All trademarks belong to Quantum Quacks.