And the LORD said unto me, Amos, what seest thou? And I said, A plumbline. Then said the Lord, Behold, I will set a plumbline in the midst of my people Israel…
— Amos 7:8
Plumbline is a free Bible app: read the text, study it down to the word, memorize it, sing from the hymnal, and hand it to someone else. Everything runs on your device and works offline. No account, no sign-in, no telemetry; your notes and study data stay local and private.
It runs in any browser, in nine languages — interface and scripture both. It follows your device's language, and you can pick one under Settings. Every text is public domain:
| Language | Bible |
|---|---|
| English | King James Version (1769) |
| German | Luther 1912 |
| Spanish | Reina-Valera 1909 |
| Arabic | Smith & Van Dyck |
| Punjabi | Free Bibles India |
| Hindi | Free Bibles India |
| French | Ostervald |
| Traditional and Simplified Chinese | Chinese Union Version (1919) |
Word-level study (the Strong's dictionary, concordance, grammar) is available where the text carries word tags — English, German, and Spanish today. The other languages are reader editions: reading, search, notes, tags, threads, weaves, memorization, and sharing all work the same.
- Passages side by side, in a browser or on a phone
- Parallel passages annotated across side-by-side chapters
- Reopens exactly where you left off, mid-chapter included
- Book → chapter → verse tap-grid navigator, marking where you have been recently
- Theme, text size, alignment, and font settings
- Optional plain-English overlay (AKJV) for easier reading
- A canon strip under the reader showing where you are in the Bible
- Tap any word for its dictionary entry, every rendering of the underlying word, and a concordance of where it appears
- The same root traced across the Old and New Testaments
- The 1769 translators' own margin notes
- Cross-references from the Treasury of Scripture Knowledge
- Search that handles partial matches, phrases, and original-language words
- Optional statistical layers — where a word concentrates, which words keep company — all computed on your device, all off by default
- Personal notes on any verse, marked in the gutter
- Tags, with a picker that offers what you already have
- Threads: a passage list built over time, with a note per entry
- Weaves: your own verse-to-verse link graph, with notes
- Convert a tag into a weave as you study
- Visualizations of your weaves: a chord diagram across the canon, and a constellation with pinnable lanes
- A notes browser over everything you have written
- Spaced-repetition memorization (SM-2) for verses or whole passages, with three drills: first letters, progressive blank-out, typed recall scored word by word
- A reading map: coverage across the canon, an activity heatmap, and a history log; chapters you have not visited lately glow
- Mark a chapter or book read by hand, on a date you pick
- Hymnal: public-domain hymns with chords the engine transposes, per-language texts, and a sing mode that scrolls continuously
- Present mode: a thread as a fullscreen, high-contrast, large-type presentation, with tap-to-focus and an "in context" fade
- Share is a QR code that puts the passage on the other person's phone
- Your church's details (time, location, website) travel with every link you share, and land as a button in the receiver's top bar
- Free. No account, no app store, no paid tier. Works offline.
- Every bit of your data backs up to a zip and restores on any device.
First launch asks who's opening the Book — new in the faith (a welcome with next steps, landing in John), curious about the Bible (for someone still deciding what they believe), sharing the gospel (straight into the Romans Road presentation), or established believer (set up study and memorization, and choose how much study detail sits beside the text). All of it is switchable any time in Settings; the text and your own notes, tags, and threads are always on. Whichever welcome you were given stays one tap away afterwards, under Welcome in the top bar.
Then:
- Read. Tap the passage button (
John 3 ▾) for the book → chapter → verse navigator, swipe (or←/→) to step chapters. - Tap a word (double-click on desktop) — the study panel opens: your note, the word's occurrences, and the dictionary entry.
- Long-press a verse (right-click on desktop) — copy, share, write a note, tag it, add it to a thread, or memorize it.
- Tag as you go, weave later. Tag passages by topic over weeks; open the tag and hit ⇔ make weave to chain them through the canon. Point two panes at linked passages and the connectors draw themselves.
- ≡ menu holds the rest: Memorize, Explore, History, Present, the guide, and Settings — including backup to a zip that restores on any device.
Put your church in Settings → Your church (name, when and where you meet, your website) and it travels with everything you share. Share in the top bar gives a QR and a link that carry both: whoever scans it gets the whole Bible, offline and free, and your church's details saved on their device — with a Church button in their top bar that opens your website. If they pass the app on, your church goes with it.
Hand a card across at a service, print the code on a bulletin, or text the
link. Nothing is registered anywhere: the details ride in the link itself
(?church=…), so you can read exactly what you are sending before you send
it, and there is no account or server involved on either end.
Sharing from Present is the same code with one difference: it opens for someone meeting the Bible rather than setting up a study tool, offering just new in the faith or curious about the Bible. Turn that off in Settings if you'd rather it behave like an ordinary share.
A weave is something you find. A thread is something you make.
Weaves are already in the Bible: Matthew quoting Isaiah, one event told in three Gospels, a Psalm on the lips of Christ at the cross. A weave writes down the connection you noticed, and from then on the reader draws it whenever either end is open — no mode to enter. A verse scrolled out of view leaves its connector pinned at the pane edge as a hint. Two views map the library: Map (book-to-book density as chord ribbons) and Constellation (one lane per weave along the canon).
A thread is yours: a set of passages you gathered in an order that makes your point — Sunday's sermon, the case you want to walk a friend through. The Romans Road is a thread. Threads are walked start to finish and carry your notes as they go.
Note
The weaves shipped with the app began life as AI-generated study aids. The
28 in the library arrive with every link marked approved, and the flag is
surfaced in the reader; anything sitting in Suggested (under Explore) is
still a proposal until you approve it against the text yourself.
Your notes, tags, threads, weaves, reading history and memory work are yours, and they stay on your device. Settings → Back up (.zip) exports all of it, and Restore from backup… loads it on any device — the archive layout is shared between the phone and the browser, so a phone backup restores in the browser and vice versa.
The KJV (public domain) comes from eBible.org's Strong's-tagged SWORD module; Strong's from Open Scriptures (CC-BY-SA); morphology from OSHB (CC-BY 4.0) and Robinson's public-domain Textus Receptus parsing; cross-references from the Treasury of Scripture Knowledge via openbible.info. The other Bibles: Luther 1912 via The Unbound Bible with Zefania Strong's tags, Reina-Valera 1909 and Smith & Van Dyck 1865 via eBible.org, the Ostervald and both editions of the 1919 Chinese Union Version via open-bibles, and the Punjabi and Hindi Bibles from Free Bibles India (CC BY-SA 4.0) — the rest public domain. The German and Spanish dictionary definitions are machine translations of Strong's, and say so in the app. Scripture renders in EB Garamond (OFL), with per-script faces (Amiri, Noto Serif) bundled the same way. Full credits and licenses, file by file: BIBLIOGRAPHY.md.
This application is built with the 1769 King James Version of the Bible, which translates the Masoretic Hebrew texts and the Textus Receptus. This is the same version that has been used for hundreds of years in English and has seen millions of souls saved and lives transformed. I argue that it is also the only version in English that satisfies the Bible's own promises about the preservation of Scripture (Psalm 12:6–7; Psalm 119:89, 152, 160; Proverbs 30:5–6; Isaiah 40:8; Matthew 5:18; Matthew 24:35; Luke 21:33; 1 Peter 1:23–25; Revelation 22:18–19).
If I did not want to use this version, I could not use any of the modern versions that so many churches use today. Below is a sampling of why that is the case:
| Version | Who holds it | The term that blocks an app like this |
|---|---|---|
| NIV | Biblica; North American commercial rights to HarperCollins Christian Publishing (News Corp) | 500 verses / 25% of the work / never a complete book. Beyond that, a negotiated commercial license. Separately: any use "in connection with artificial intelligence, machine learning, large language models, chatbots, or similar technologies requires a valid license." Terms |
| ESV | Crossway | 500 verses / half a book / 25%. And: "The ESV text may not be quoted in any publication made available to the public by a Creative Commons license." Their API is online-only, non-commercial, and licensed "to organizations, not to individuals or solo developers." Terms · Permissions |
| NKJV | Thomas Nelson → HarperCollins Christian → News Corp | 500 verses / 25%; the text is "not to be reproduced except as permitted in writing." Permissions |
| NASB | The Lockman Foundation | 1,000 verses / 50% / never a complete book; beyond that, a signed request form. Terms |
| Amplified | The Lockman Foundation | Same terms as the NASB. Terms |
| NLT | Tyndale House Publishers | 500 verses / 25% / never a complete book. Permissions |
| CSB | Holman Bible Publishers / Lifeway | 1,000 verses / 50% / never a complete book. Permissions |
| The Message | Eugene Peterson estate / NavPress, licensed through Tyndale | 500 verses / 25%. Permissions |
| NRSV | National Council of Churches, via Friendship Press | Closed. Except for the Catholic Edition, the NRSV "is no longer available for new licenses or permission agreements." There is no price at which you may ship it. Licensing |
| NRSVue | National Council of Churches; rights brokered by Petradi International Rights Services | License required, routed through an outside rights-management firm. Guidelines |
| RSV | National Council of Churches | License required, same channel. Licensing |
| Good News (GNT) | American Bible Society | 500 verses / 50% of a book / 25% of the work. Rights |
| CEV | American Bible Society | Same terms. Licensing |
| NABRE | Confraternity of Christian Doctrine (the US bishops) | Under 5,000 words / 40% of a book / 40% of the work. Royalty income is an explicit purpose of the copyright. Permissions |
| NET | Biblical Studies Press | The near miss: 500 verses free, but distributing the full text "in any form other than paper" requires written permission and compliance with their content-control guidelines. Permissions |
A worthy exercise I leave with the reader is to click on any one of the license agreements above and see how it reads when you replace the name of their intellectual property with "The Word of God". It did not sit well with me when I did.
For these reasons, I have chosen to use the King James Version of the Bible. I have included Strong's Concordance and other study tools to help where a word might be unfamiliar, and if it remains a challenge for you, there are other Bible applications that will provide some of the versions listed above. I do, however, implore you to consider your translation selection carefully, as many parts of Scripture have been omitted or changed in modern versions, namely:
- Matthew 17:21
- Matthew 18:11
- Matthew 23:14
- Mark 7:16
- Mark 9:44
- Mark 9:46
- Mark 11:26
- Mark 15:28
- Luke 17:36
- Luke 23:17
- John 5:4
- Acts 8:37
- Acts 15:34
- Acts 24:7
- Acts 28:29
- Romans 16:24
And the following passages are bracketed, footnoted, or marked as later additions:
- Matthew 6:13b
- Mark 16:9–20
- Luke 22:43–44
- Luke 23:34a
- John 7:53–8:11
- 1 John 5:7–8
The code is MIT — LICENSE. The text and the lexical data keep their own terms (public domain, CC-BY 4.0, CC-BY-SA); the carve-out at the end of LICENSE names them directory by directory, and BIBLIOGRAPHY.md has it file by file.
May God bless you as you read His Word, whether here or elsewhere, and don't fail to share it with others.