# Second Tiger (두번째호랑이) > A one-person software label registered in the Republic of Korea. It builds and > operates games, mobile apps, developer tools, Atlassian Marketplace apps and a > web service. Every product is planned, built, released and run by one person. Legal name: Second Tiger (두번째호랑이). Sole proprietorship, Republic of Korea. Business registration number 670-56-01033. Established 27 August 2026. Located in Gapyeong-gun, Gyeonggi-do. Contact support@secondtiger.com. Founder and sole operator: Youngjune Kwon (https://github.com/YoungjuneKwon), a developer with more than 20 years of experience. Some items below were built for other owners; ownership is noted where it differs. ## Games - [Badanori (바다놀이)](https://secondtiger.com/badanori/): A small island entered from a browser at https://badanori.com, no install and no sign-up. Walk the beach, swim, snorkel and freedive to a coral colony; a humpback whale and her calf circle the island along with dolphins, turtles, crabs and seabirds (25 animals, positioned by the server so every visitor sees them in the same place). The island follows Korea Standard Time with the sun computed from date and coordinates; the night sky shows 3,008 catalogue stars, the Milky Way, the Moon's phase, four planets and the ISS. Visitors can place a sunbed, towel, parasol or campfire and sit or lie at them, and can leave a 30-second recorded 'ghost' of their movements that others see within 20 metres. Up to 60 people per room, more than 80 characters. No dive timer, records or breath gauge by design. Korean interface. Free. - [Far Ithaca](https://apps.apple.com/kr/app/id6817797611): Strategy defense game set in Greek mythology. Travel island to island across a sea chart; 21 gods each speak in their own voice. iOS, version 1.5, released on the App Store 2026-10-08. Korean, Japanese and English. Google Play in preparation. - Beyond the Loop: Text adventure played through conversation. A train absent from the timetable, set around Seoul Subway Line 2. Unreleased, in development. ## Developer tools - [ValetFS](https://apps.apple.com/kr/app/valetfs/id6804526734): Keeps credentials such as API keys on your phone and lends them to an AI agent's computer only while you allow it. They stay in memory and are never written to disk. iOS, version 1.1.2, Developer Tools. Daemon and CLI are open source at https://github.com/WinM2M/valet-fs. - [Just Replace HTTP](https://chromewebstore.google.com/detail/just-replace-http/fbjhclldebdeldkbcadnegkdjbdpdfag): Chrome extension that redirects HTTP request URLs to other addresses using regular-expression rules you can toggle. Uses Manifest V3 declarativeNetRequest, so rules run inside the browser and nothing is sent anywhere. Version 1.3.0. Free, no account, no ads. - [ten-line-transformer](https://github.com/YoungjuneKwon/ten-line-transformer): A working transformer in a single 123-line Python file. One training step takes ten of those lines and runs on a CPU in under a minute. Every part is mapped line by line to the shipping implementations in Qwen2.5, Llama and OLMo 2. Open source. ## Work and planning - [Proveri](https://proveri.ai/): Survey platform where the respondent set is specified rather than left to whoever arrives. Target counts by gender, age group, education, major, region, occupation and country; branching and display logic decide what each respondent sees. Survey design, up to 2,000 completed responses per project, and the analysis suite are free; only AI synthetic respondents are paid. Operated by WinM2M Inc. - [Gantt Forecast for Jira](https://marketplace.atlassian.com/apps/3591000852/gantt-forecast-for-jira): Jira Gantt chart that compares planned work against actual completion and gives a Bayesian estimate for the work that remains. Atlassian Marketplace. - [Markdown Export (Faithful) for Confluence](https://marketplace.atlassian.com/apps/1569868747/markdown-export-faithful-for-confluence): Exports a Confluence page tree or a whole space to Markdown with attachments, links and readable filenames. Each export ships a report listing everything that degraded during conversion. Atlassian Marketplace. - [DiligentHours](https://github.com/YoungjuneKwon/diligent-hours): Windows and macOS desktop timer that treats the first input of the day as the start of work and counts down the time remaining in the agreed work hours. Lives in the system tray, records no input content, works entirely offline. Version 0.5.0, built with Tauri and Rust. Open source. ## Personal insights - [Sidera: Korean Astrology](https://apps.apple.com/us/app/sidera-korean-astrology/id6806914044): Computes the sky and the four pillars (saju) of the moment you were born and talks with you about what is there. The basis for each calculation can be inspected. iOS, version 1.5.0, Lifestyle. Contract development; the App Store seller is a different party. ## Optional - [Site](https://secondtiger.com/): This page, in English and Korean. - [GitHub](https://github.com/YoungjuneKwon): Open-source repositories by the founder. ## Lab Small browser demos and practice pieces, listed at https://secondtiger.com/lab/. Not products. - [Mechanics Lab](https://secondtiger.com/lab/mechanics/): Drop crates and change gravity, restitution and friction to see what happens. three.js with cannon-es, works with touch. Built in opencode with EXAONE (k-exaone_v2.5). The last remaining bug was fixed by GPT-6.1-sol.