Projects by Junhua

What I'm building.

MarginDeck is my current focused project. TakaQuiz runs alongside it. Both grew from the same operating questions I explore throughout SwingCodeLab.

macOS

MarginDeck

See what each product earns after costs.

MarginDeck brings product revenue, scheduled costs, and estimated contribution profit together on your Mac, with a menu bar brief for quick checks between deeper reviews. Version 1.6.0 adds optional AI Connections for Claude and Codex on the same Mac, so you can query reports and prepare records for review in MarginDeck.

  • Check revenue, cost, or contribution profit from the menu bar, with a comparison against the full previous month when saved history is available.
  • See the next 7 or 14 days of scheduled costs, including annual charges, and open the underlying details.
  • Choose a weekly financial check-in reminder and see when revenue was last saved.
  • Compare recorded revenue, scheduled costs, and estimated contribution profit over 6 or 12 months.
  • Build local monthly RevenueCat and Stripe history from successful 1.4 syncs onward.
  • Convert supported amounts into estimated totals in your display currency while preserving original amounts.
  • Allocate shared costs across products and keep working data local to the Mac.
Relationship

MarginDeck is made and published by Junhua, the publisher of SwingCodeLab.

Scope

MarginDeck is a planning and estimation tool. It is not accounting, bookkeeping, tax, or financial-advice software, and its outputs should not replace professional records or advice.

Web · Chrome · Firefox · Edge

TakaQuiz

Turn your notes, PDFs, and photos into a quiz.

TakaQuiz is an AI quiz generator that writes practice quizzes from your own notes, PDFs, photos, or a web article, and shows the line in your material that each answer came from. It runs on the web, with Chrome, Firefox, and Edge extensions for quizzing the page you're reading.

  • Start from typed or pasted notes, a PDF, a photo of a page, a web article link, or a pasted video transcript.
  • Every answer shows the line in your material it came from.
  • A missed question comes back the next day, then after 3 and 7 days, until you answer it correctly on three separate days.
  • Quiz the page you're already reading with the Chrome, Firefox, or Edge extension.
Relationship

TakaQuiz is made by Junhua, the publisher of SwingCodeLab, and run by Fiveupclub Inc, his company.