KyBook 3 Alternatives for iPhone and iPad in 2026

If you opened KyBook 3 recently and it crashed, froze, or just felt left behind on a new iOS version, you are not imagining it. The app that built a loyal following for its OPDS catalogs and self-hosted library access has gone quiet, and people who relied on it are now hunting for something that still gets updates. This post is for them: a comparison of what KyBook users actually need, and which iPhone and iPad readers cover it in 2026.

KyBook was good. That is worth saying up front. Its OPDS support was mature, it read a long list of formats, and it gave power users a lot of control. So the goal here is not to pretend it was bad. It is to find a replacement that keeps the parts you depended on, and to be honest where a modern reader does something differently or not at all.

What happened to KyBook 3?

KyBook 3 has not seen meaningful development for a long stretch. There are no recent updates, the developer has been silent, and on newer versions of iOS users report layout glitches, sync that no longer connects, and outright crashes. Whether the app still launches for you depends on your exact device and iOS version, but the trend is clear: it is not being maintained, and an unmaintained reader is a library you cannot trust.

That matters more for a reader than for most apps. Your books, reading positions, and catalog connections all live inside it. When Apple changes how file access or networking works in a new iOS release, a maintained app ships a fix and an abandoned one breaks. If KyBook is still limping along for you today, treat that as borrowed time rather than a stable setup.

So the practical question is not "is KyBook dead." It is "what do I move to, and will it still work next year."

What KyBook users actually relied on

Before comparing replacements, it helps to name what made KyBook worth defending. Most people who search for an alternative are not asking for "any ebook app." They want specific capabilities back. From what KyBook was known for, the list usually comes down to:

• OPDS catalogs. Browsing and downloading books straight from a catalog URL, including public libraries like Project Gutenberg and self-hosted servers.
• Self-hosted library access. Connecting to a Calibre server or similar on your own network instead of buying everything from a store.
• Format breadth. KyBook read EPUB, FB2, PDF, and more, which appealed to people with mixed collections.
• Control over the page. Fonts, margins, spacing, and themes you could actually tune.
• Owning your files. No store lock-in, no DRM wall around your own books.

Use that as your checklist. The right replacement is the one that covers the items you personally care about, not the one with the longest feature list. For most former KyBook users, OPDS and self-hosted access sit at the top.

OPDS support in 2026 iOS readers

OPDS is where KyBook earned its reputation, so it is the first thing to test in any replacement. A reader either speaks OPDS properly or it does not, and a lot of mainstream apps simply do not. Apple Books has no concept of it. Kindle has no concept of it. If catalog browsing is why you used KyBook, you can rule out most of the obvious names immediately.

justRead is built around this need. You add a catalog by URL, browse it inside the app, search the server directly rather than downloading everything first, and page through large catalogs without the app choking. Project Gutenberg is built in, so you have tens of thousands of free public-domain titles available the moment you install it, with no setup at all.

OPDS servers that work in justRead

For self-hosters, the catalog source matters. justRead connects to custom OPDS servers including:

• Calibre's built-in OPDS feed
• calibre-web
• Kavita
• Komga
• COPS (Calibre OPDS PHP Server)

If you ran one of those behind KyBook, the move is mostly just re-entering the URL. The browsing model is familiar: open the catalog, search or page through it, tap to download into your library. Server-side search means the work happens on the server, which keeps things fast even when the catalog holds thousands of books.

If you point a reader at a server it cannot reach, that is a network or server-side issue rather than an app one, so the same checks you used to do for KyBook (correct URL, server reachable on your network, credentials right) still apply.

Calibre: the other half of self-hosting

A lot of KyBook users were really running a Calibre setup and using the app as the phone-side client. If that is you, OPDS is one option, but justRead also offers a more direct route: a two-way Calibre Content Server connection.

It finds your Calibre server over Wi-Fi automatically, or you can enter it manually. You pick which books to pull, or tap "Select New & Changed" to grab only what is new since last time. Then it syncs both directions: reading progress, highlights, and ratings flow back to Calibre, so the desktop library and the phone stay in agreement instead of drifting apart. It handles multiple libraries and HTTP Digest authentication, and it syncs PDFs alongside EPUBs.

That is a step beyond what most readers do with Calibre, and beyond a one-way OPDS download. If you walk through the Calibre sync workflow, it covers discovery, badges for new and changed books, and what gets written back. For a former KyBook user, this is often the single biggest upgrade in the move.

Feature comparison: KyBook 3 vs justRead

Here is the honest side-by-side. KyBook wins on raw format breadth, and there is no point hiding that.

The format row is the trade-off to weigh seriously. KyBook read FB2 and DJVU; justRead reads EPUB and PDF, nothing else. If a meaningful slice of your collection is FB2 or DJVU, you have a choice to make: convert those files (Calibre converts FB2 to EPUB cleanly in bulk), or keep a second app around for the stragglers. Pretending the gap does not exist would just set you up for disappointment, so plan for it before you migrate.

Everything else leans toward a maintained app. Two-way Calibre sync, written-back highlights, and detailed reading stats are real upgrades, and an app that ships updates will keep working as iOS changes underneath it.

Other alternatives worth considering

justRead is not the only option, and depending on your collection another app may fit better.

• Marvin was the classic power-user EPUB reader on iOS, and its situation is worth understanding before you commit; we cover where it stands now in Marvin 3 in 2026: still working?. If you are weighing an actively developed alternative against it, the Marvin 3 alternative page lays out the comparison.
• Apple Books is free and built in, but it has no OPDS, no self-hosted access, and minimal control over typography. For a former KyBook user that is a downgrade on every axis you cared about, though it is fine as a casual second reader.
• Moon+ Reader comes up in these discussions, but it is Android only. There is no iPhone or iPad version, so it is a non-starter on iOS no matter how often it is recommended.
• Panels is excellent if part of your library is comics or manga in CBZ/CBR, which a general EPUB reader will not handle. It is a companion, not a replacement, for a reflowable-text setup.

For a wider survey of what is current on iOS, the best EPUB reader apps for iPhone and iPad roundup compares the field without assuming you came from KyBook.

How to migrate from KyBook 3

Moving over is mostly about getting your files out of KyBook (or out of wherever you store the masters) and into your new reader. There is no special importer; it is a normal file handoff.

1. Find your master files. If your books live in Calibre or in a cloud folder, that is your source of truth and you can skip exporting from KyBook entirely. If they only exist inside KyBook, use its export or share options to get the EPUBs out to the Files app first, while the app still launches.
2. Convert anything that is not EPUB or PDF. Run FB2 and DJVU files through Calibre to produce EPUBs. Do this now, before you uninstall anything, so you are not stuck later.
3. Reconnect your catalogs. In your new reader, re-add your OPDS servers by URL, or connect the Calibre Content Server over Wi-Fi. This is usually the fastest part since you are just re-entering known addresses.
4. Import loose files. For one-off EPUBs and PDFs sitting in Files, iCloud, Dropbox, Google Drive, or OneDrive, open them into the app or point the app at the folder. On iPad you can also drag and drop files straight in.
5. Confirm before you delete. Open a few books, check that positions and catalogs look right, then remove KyBook once you are satisfied nothing was left behind.

The cloud-folder approach is worth a mention for people who hate duplicating files. Instead of importing every book into the app's own storage, you can point justRead at a folder in iCloud, Dropbox, Google Drive, or OneDrive and read from there, keeping a single copy of each book.

FAQ

Does justRead support OPDS like KyBook did?

Yes. You can add OPDS catalogs by URL, browse and search them in the app, and download into your library. Project Gutenberg is built in, and custom servers including Calibre OPDS, calibre-web, Kavita, Komga, and COPS are supported. For self-hosted setups it also offers a two-way Calibre Content Server connection that goes beyond plain OPDS download.

Can justRead read FB2 or DJVU files?

No. justRead reads EPUB and PDF only (PDF is read-only). This is the main thing KyBook did that justRead does not. If you have FB2 or DJVU books, convert them to EPUB in Calibre first, which handles FB2 cleanly in bulk, or keep a separate app for those formats.

Does justRead sync with Dropbox or Google Drive?

Yes. It syncs across your own devices via iCloud (CloudKit), and you can also point it at any cloud folder it can reach, including Dropbox, Google Drive, and OneDrive. Calibre Content Server sync and OPDS catalogs are additional ways to get books in.

Is KyBook 3 still on the App Store?

Its status has been uncertain for a while, and even when it installs it is not maintained, so newer iOS releases can break parts of it. Even if you can still download it today, treating it as a long-term reader is risky. That is the reason most people end up looking for an alternative in the first place.

Will my reading progress carry over from KyBook?

Not automatically. There is no direct import path between the apps. If your library is managed in Calibre, sync from there and your progress lives with the server going forward. For loose files, you import the EPUBs and start fresh on reading position.

Picking a reader you can keep

The hard part of replacing KyBook is not finding an app that reads EPUBs; plenty do. It is finding one that keeps your OPDS catalogs and self-hosted library working and is still being updated a year from now. That second condition is what KyBook stopped meeting.

If OPDS and self-hosted Calibre were the reasons you stuck with KyBook, justRead covers both on iPhone and iPad, with two-way Calibre sync and built-in Project Gutenberg access. Just go in knowing it is EPUB and PDF only, and convert anything else before you switch.

To go deeper, see how its OPDS reader handles custom catalogs, walk through the Calibre sync setup, or compare the wider field in the best EPUB reader apps for iPhone and iPad roundup.