Apps by Pengfan Chang

Native tools and subscriptions for research, writing, media libraries, and academic workflows.

Start with the apps: SwiphtNum for statistical computing, SA_agent for Google Scholar summaries, SwiphtPapers for deliberate notes, and iThrea for private media browsing.

See the apps Subscribe to SA_agent

SwiphtNum US$4.99/mo

SA_agent US$10/mo

SwiphtPapers Free + Advanced

iThrea US$0.99/mo

Choose an app

Each product has a direct path to purchase, subscription, support, and privacy details.

All projects

macOS statistics app

SwiphtNum

Prepare datasets, run guided analyses, automate repeatable work with SCL, and export publication-ready results from a native Mac workspace.

Price: US$4.99/mo or US$49.99/yr
Trust point: Local Swift analysis engine

View SwiphtNum on the App Store Explore SwiphtNum

Google Scholar extension

SA_agent

Add journal ranking badges and paid AI summaries to Google Scholar with transparent usage accounting and server-side provider access.

Price: US$10/mo or US$100/yr
Trust point: Creem checkout and rollover credits

Subscribe to SA_agent How SA_agent works

Markdown notes for Apple platforms

SwiphtPapers

A deliberately constrained note app: ten color-coded Markdown papers across iPhone, iPad, Mac, Apple Watch, and Apple Vision Pro.

Price: Free, Advanced from US$3.99/mo
Trust point: Private iCloud sync

Discover SwiphtPapers Read privacy model

Private media library shell

iThrea

Browse Emby, WebDAV, and local-folder media libraries through a shared Apple-platform interface built around user-controlled sources.

Price: US$0.99/mo or US$5.99/yr
Trust point: No hosted media library

Explore iThrea View terms

Why buy here

Clear billing paths

App Store subscriptions for native apps; Creem checkout for SA_agent credits.

Privacy-first defaults

Products are designed around local files, private iCloud data, user-selected servers, or numbered accounts.

Built by one accountable maker

Support, policies, documentation, and product pages live together on jpfchang.org.

Built by Pengfan Chang (John)

I build native apps, privacy-first products, academic tooling, and open web projects across macOS, iOS, iPadOS, watchOS, visionOS, Android, GNU/Linux, and the web.

About the builder Contact support

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Recent Writing

Terminal Verse & Trail Notes Nov 10, 2025 · 4 min read A November status report covering the new terminal aesthetic, daily KJV verse card, and what I've been hacking and hiking lately. UI Polish and Focus Update: Minimalism, Clarity, and New Directions Oct 19, 2025 · 7 min read Comprehensive UI/UX refinements including TornadoVPS-inspired minimalism with Intel One Mono, removal of all decorative icons, improved donation UX, and announcing my current focus areas: GNU Hurd and Apple devices.

>_ Enter the terminal

A command-line path through this site, including arcade games and the older portfolio trail.