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PETRA
Worship without limits
Built for Sunday services and worship gatherings,
making slide preparation effortless,
so the flow of worship is never limited by technology.
Download for Windows View changelog
The installer is unsigned — the download page explains SHA-256 verification and the SmartScreen "More info → Run anyway" prompt.
PETRA — project list screen

At a glance

Works offline
Core features free
Data stays local
No interruptions
Verified SHA-256
Online updates
Virtual camera
Single instance
Works offline
Core features free
Data stays local
No interruptions
Verified SHA-256
Online updates
Virtual camera
Single instance

Our promises

Projection must work offline

Core projection runs entirely on your machine. Network calls may fail, time out or quietly fall back — the service goes on.

Never interrupts the service

Notices are fetched once at startup and never pop up mid-service; at most one notice per launch.

Core features are free

Core projection stays free; see the download page and pricing for exactly what each tier includes.

Features

Beautiful built-in backgrounds

Static and motion backgrounds work out of the box — hover to preview motion effects and set the atmosphere in one step.

Virtual camera and NDI

Two streaming modes — virtual camera and NDI — for Tencent Meeting, Zoom, DingTalk, Teams and broadcast software.

Widescreen, standard, portrait

Switch between 16:9, 4:3 and 9:16 at will; projection output is separate from the preview, so any screen is covered.

A rich built-in hymn library

Tens of thousands of hymns built in, searchable by title or lyrics in seconds, with simplified/traditional pairing your team can extend.

A built-in Bible tool

All 66 books of the Chinese Union Version built in — jump by book, chapter or verse and insert the passage into the flow.

Online updates

Checks, prompts and installs updates inside the app; silently skipped when no update source is configured.

SHOWCASE

Open PETRA and the service is ready

From building a project to picking songs, looking up Scripture and streaming live — every screen is something you actually use on a Sunday.
Hymn library screen

A rich built-in hymn library

Over 60,000 hymns ready to use: search by title or lyrics in seconds, with simplified/traditional pairing. Songs your team writes or adapts are available immediately. Search · Simplified/traditional · Your own songs

A built-in Bible tool

The 66 books of the simplified Chinese Union Version are built in, indexed by book, chapter and verse. Select a passage and insert it into the flow — no more flipping through a printed Bible during the reading. 66 books · Fast lookup · Insert in one tap
Scripture selection panel
Streaming settings screen

Streaming that keeps the room and the internet in sync

The virtual camera shows up in Tencent Meeting, Zoom, DingTalk and Teams; NDI output feeds vMix, OBS and other switchers — the room and the online congregation see the same picture. Virtual camera · NDI · Meetings and switchers

Pick a song, insert it, done

Search built-in and your own songs by title, preview the full lyrics on the right, then insert the song into the flow — a few steps from finding a hymn to putting it on screen. Search · Preview · Insert
Hymn selection panel

Made for these gatherings

Sunday service

Worship lyrics, the Scripture reading and sermon slides advance in one flow; output and preview are split so each volunteer knows their job.

Worship night

Songs, harmonies and media switch with the rhythm of worship; singers and musicians stay in step and nothing drops.

Harp & Bowl

Quiet gatherings with minimal, unhurried lyrics that stay out of the way and a stable screen through long sessions.

Live streaming

Virtual camera and NDI feed your meeting or broadcast software, keeping the room and the online congregation on the same picture.

Seasonal services

Christmas, Easter and other seasons: festive backgrounds and songs are ready out of the box, so decorating takes minutes.

Training and discipleship

Course slides and team training go straight on screen, fully offline with no dependence on the venue's Wi-Fi.

Subscription pricing

Free

Core projection free

Core projection features and everyday assets — enough for individuals and small gatherings.

  • Core projection features
  • Built-in hymn library
  • Built-in Bible library
  • Solid-color and image backgrounds
¥0 Core features, free forever

Pro

Limited-time free

Adds media and streaming, so Sunday morning and the online congregation are covered.

  • Everything in Free
  • Up to 3 devices
  • Video backgrounds
  • Audio and video file playback
  • PPT import (.ppt / .pptx)
  • Widgets: graphics · clock · countdown
  • Multiple polished transitions
  • Virtual camera output
  • NDI output
¥199 / year Limited-time free

Max

Coming soon

For more advanced services; availability will be announced.

  • Everything in Pro
  • More advanced and cloud features
  • Not available yet — stay tuned
Coming soon

Developer: Threshing Floor of City (TFoC)

Threshing Floor of City (TFoC) logo

PETRA is developed and maintained by Threshing Floor of City (TFoC). For positioning, release policy and contact details, see the About page.

More about PETRA

Download and verify

Installer details, three ways to verify SHA-256, and how to get past SmartScreen.

Learn more

Changelog

New features, fixes and known issues for each version; version numbers map to git tags.

Learn more
Threshing Floor of City banner

About and contact

What PETRA is for, how we handle privacy, and how to reach the developer.

Learn more

Frequently asked questions

There are three tiers. Free covers core projection plus the built-in hymn and Bible libraries and solid-color/image backgrounds. Pro adds video backgrounds, audio/video playback, PPT import, widgets (graphics, clock, countdown), multiple polished transitions, virtual camera and NDI output — currently free for a limited time. Max is not available yet; availability will be announced officially.
No. Projection runs entirely on your machine and works offline; the network is only used to check for updates and fetch startup notices, and failures are skipped silently.
The first release does not use a code-signing certificate, so Windows shows a SmartScreen warning. Every installer's SHA-256 is published, and you can check it with Get-FileHash or certutil on the download page. Once the hash matches, click "More info → Run anyway" to continue.
No. Projects, songs and assets stay on your computer. Analytics use only an anonymous identifier and event type — no names, emails or phone numbers, and IPs are not stored for tracking.
Windows 10 or 11 (64-bit). Projection works fully offline; see the pricing section for what each tier includes.
Still have questions?
Contact us

Ready to start projecting?

Download the installer, verify its SHA-256 on the download page, and you are projecting within minutes.
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