Helpful notes for better studying.
EPUB & PDF · Android · Study · Privacy
Features & Study
The Art of the Aside: Inline Footnotes, Tactile Citations, and Preserving the Reading Flow
Explore GemReader's overhauled footnote infrastructure. Learn how dual-engine inline popup cards, one-tap haptic copy, graphic quote card sharing, and BiDi typography preserve your cognitive flow during deep reading.
Discover seamless inline footnotes in GemReader. Explore dual-engine rich text rendering, one-tap haptic citation copying, styled quote card sharing, and full RTL layout support.
Read guideFeatures & Study
Elevating the Margins: Structured Markdown and the Art of Digital Marginalia
Transform raw annotations into structured marginalia with full Markdown support. Format headings, lists, blockquotes, and links across text highlights, image notes, and the Gems Library.
Privacy & Control
Defense in Depth: Inside GemReader’s Multi-Layered PIN and Window Security
An engineering analysis of how GemReader bypasses system keyboards with custom touch primitives, coordinates reference-counted FLAG_SECURE window masking, and unwraps AES-GCM vault keys.
Features & Study
Best Free EPUB Readers for Android in 2026 (Honest Picks by Use Case)
There is no single best EPUB reader for Android — there is a best one for how you read. Six free apps, what each is actually good at, where each falls short, and a straight answer for comics, e-ink, sync, privacy and studying. Written by the makers of one of them, with that bias declared up front.
Features & Study
How to Turn Ebook Highlights into Flashcards on Android (3 Ways)
Highlighting a textbook feels productive and mostly isn't — the highlight sits there and you never see it again. Here are the three ways to get highlights from an EPUB, PDF or Kindle book into a spaced-repetition deck on Android, from the manual export route to a reader that does it without any export at all.
Formats & Files
How to Open AZW3 and MOBI Files on Android (Without the Kindle App)
An AZW3 or MOBI file either opens in any decent Android reader or opens in nothing but Kindle — and the difference is a single flag in the file header. Here is how to tell which one you have in ten seconds, which readers open the free ones, and what to do about the locked ones.
Formats & Files
How to Check if an EPUB Has DRM (3 Ways, One Trap)
An EPUB is a zip file. Whether it is locked comes down to two small files inside it — and one of them fools almost every checker. Here is how to read them yourself, or let a tool do it in your browser without uploading the book.
Privacy & Control
The Locksmith's Puzzle Box: Inside GemReader’s Secure PIN Entry
Explore how GemReader leverages direct touch keypads, screenshot blocking, and AES-GCM cryptography to build an impenetrable sanctuary for your private locked libraries.
Features & Study
The Commonplace Cabinet: Transform Your Highlights Into Long-Term Memory
Highlights shouldn't sit in a digital graveyard. Discover how GemReader's Anki export converts your reading notes directly into spaced repetition flashcards.
Privacy & Control
The Traveling Trunk: Expand Your Bookshelf with Secure, Boundless Storage
As your library grows to hold dense textbooks and audio-rich chapters, your internal memory can fill up quickly. Discover how GemReader's Verified External Storage Migration lets you safely move your entire secure library to a micro-SD card.
Features & Study
The Complete Guide to Audio Options in GemReader: From Custom Audiobooks to Local Neural AI
Transform your reading sanctuary into a personalized listening room. Discover how GemReader's unified Audio Hub gives you total control over how your books sound—without compromising on speed, privacy, or storage efficiency.
Architecture & Performance
Behind the Tech: Dual-Engine TTS — Native Voices vs. Local Neural AI
Whether you are a visual learner, an auditory processor, or someone who blends both, your reading app should adapt to you. Discover how GemReader's completely offline Dual-Engine TTS architecture delivers both lightweight system voices and hyper-realistic Neural AI.
Features & Study
Bridging Audio & Text: Real-Time Synchronized Highlighting and Hands-Free Reading
Experience the ultimate blended learning environment. Discover how GemReader synchronizes audio playback with active text highlighting to perfectly merge visual and auditory focus.
Features & Study
Transform Your EPUBs into Audiobooks: Attaching Publisher Tracks and Custom Audio per Chapter
While AI-generated voice synthesis is great for general reading, nothing replaces human narration. Discover how GemReader allows you to attach custom pre-recorded audio files directly to individual chapters.
Privacy & Control
Turning the Tumblers: Why GemReader’s PIN is a Vault, Not a Password
A PIN should be more than just a polite request for your phone to hide a folder. It should be the physical tumblers of an iron-clad vault. Here is how GemReader bypasses the leaky OS to give you true mechanical-grade security.
Features & Study
Deep-Dive Study Without a Trace: Ephemeral Cross-Book History
When deep research demands jumping between texts, you need a thread to guide you back—but not one that leaves a permanent trail. Discover GemReader's in-memory, session-based Reading History.
Design Philosophy
Customizing Your Library: Introducing Enhanced Color Swatches & Adaptive Covers
Whether you have a digital library of ten books or ten thousand, organizing your collection should feel personal, readable, and visually refined. Discover GemReader's updated Library Color Swatch system and dynamic theme adaptation.
Features & Study
The Digital Commonplace: Turning Favorite Passages into Beautiful Quote Cards
Sharing profound book passages shouldn't mean losing their beauty and context. Discover how GemReader's Excerpt Quote Card Generator transforms selected text into elegant, custom-styled graphics with a single tap.
Design Philosophy
Adaptive UI Engineering & Context-Aware Security: Designing the Intelligent Workspace
A reading interface should intuitively adapt to your device and respect your privacy. Discover how GemReader's layout engine dynamically scales its tools and automatically suppresses data extraction when reading inside Locked Collections.
Features & Study
From Text Selection to Flashcards & Instant Lookup: Keeping Your Focus
When you run into an unfamiliar word or a concept you need to memorize, switching apps breaks your concentration. Discover how GemReader integrates SRS flashcards and offline dictionaries directly into your reading flow.
Features & Study
Smart Highlighting & Color-Coded Note-Taking: Designing Your Mental Map
Highlight in six distinct colors, attach rich Markdown notes, and explore your insights instantly in the Gems Library sidebar. Discover how GemReader turns passive text into active learning.
Features & Study
The Top Shelf: Keeping Your Absolute Favorites Close at Hand
Sorting through a vast digital library shouldn’t feel like searching for a needle in a haystack. Discover how GemReader’s new Favorites feature lets you instantly spotlight your most cherished books and study guides.
Features & Study
The Reader’s Lens: Uncovering the Micro-Worlds Within Your Books
An image inside an eBook shouldn’t be a static, low-resolution bottleneck. Discover how GemReader’s new interactive image viewer brings hidden details into sharp focus with seamless tap-to-zoom and canvas panning.
Design Philosophy
The Digital Scroll: Honoring the Past While Navigating the Present
From ancient clay tablets to modern touchscreens, the physical shape of literature has always evolved alongside human ingenuity. Discover why GemReader embraces vertical scrolling as the natural rhythm for mobile reading, and how we are exploring ways to bring the classic page-turn into the digital era.
Universal Accessibility
Reading the Signs: Navigating Your Library in Your Own Language
Software shouldn't feel like a foreign territory. Discover how GemReader bridges the linguistic gap with native system menus, and how we are working to make library navigation effortless for readers across the globe.
Design Philosophy
The Invisible Frame: Why the Best Typography is the Kind You Never See
Typography should be a bridge to a book’s message, not a barrier to entry. Discover GemReader’s unique approach to automated, language-inclusive typography, and why we chose compassion and simplicity over endless settings menus.
Privacy & Control
The Gatekeeper: Why an App Lock Option Belongs on Your Bookshelf
Sometimes the biggest threat to your reading privacy isn't a complex digital security breach—it is simply handing your phone to a loved one. Discover how GemReader leverages native Android security APIs to act as a gentle, private latch for your literary sanctuary.
Privacy & Control
Navigating the Crowds: Defeating Shoulder Surfers in Public Spaces
Your reading list is your business, no matter how crowded the space. Discover how GemReader’s new custom cover masking and text renaming features keep your library entirely safe from nosy onlookers.
Features & Study
The Shared Library: Spreading Knowledge Beyond the Margins
GemReader is built to give your books an iron-clad private sanctuary, but security doesn’t mean isolation. Discover how our open, zero-DRM architecture allows you to easily share your favorite EPUBs and pass the joy of reading along to friends.
Design Philosophy
Shaping Your Sanctuary: How GemReader’s Themes Honor the Rhythm of Reading
A book remains unchanged regardless of where you read it, but the environment alters how you receive it. Discover how GemReader’s intentional color themes transform your screen from a sterile glass device into a custom sanctuary for your mind, with full light and dark mode support across every palette.
Privacy & Control
Guarding Your Secret Gardens: How GemReader Protects Your Most Personal Books
In a world that demands you share everything, some books are meant for your eyes alone. Discover the absolute privacy of GemReader's PIN-locked vaults.
Design Philosophy
Mapping Your Journey: How GemReader Brings the Physical Feel of Progress to Your Digital Screen
On a flat glass screen, a 900-page epic looks exactly like a 10-page essay. Discover how GemReader elegantly restores the intuitive sense of progress lost in digital books.
Features & Study
Unearthing Your Reading 'Gems': How GemReader Reinvents Book Notes
Traditional e-readers treat your insights like hidden rocks. Discover how GemReader surfaces your annotations and brings interactive workbooks to life — the kind you can actually type your answers into.
Privacy & Control
Welcome to Your Private Library: Importing Your ePubs
Taking control of your digital bookshelf starts with true data ownership. Learn how GemReader lets you import your ePub files completely offline with zero server synchronization.
Privacy & Control
Order in the Library: Introducing Nested Collections
Master your digital wardrobe with up to three levels of folder organization and automatic security inheritance.
Product Updates
The Rhythm of the Page Turn: Introducing Pages Mode
We thought the modern vertical scroll was all a digital library needed. We were wrong. Discover our new pagination toggle, built directly from your feedback.
Feature Updates
Mapping Your Milestones: The All-New GemReader Progress Bar
Discover how our elegant new progress indicators bring the intuitive, satisfying momentum of physical reading into your digital bookshelf using a concept you already use every day.