SideBooks vs Flippy
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SideBooks
This app offers a high-performance PDF and comic viewer with realistic paper-turning animations. It supports various viewing directions, enhanced bookshelf management, and secure password protection for your documents. Easily import files from multiple sources and enjoy a customizable reading experience.
- Realistic paper curl animation
- Multiple viewing directions
- Enhanced bookshelf management
- Password protection
- Dropbox and iTunes file import
- Supports PDF, ZIP, CBZ, RAR, CBR
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SideBooks is a high performance, high speed PDF viewer that allows you to enjoy reading with the feel of actual paper. =Features= Curl animation that simulates the actual turning of paper pages has been added to the standard page slide function. Supports viewing from 3 directions, documents that open left to right, right to left and vertically. It provides the optimal environment for viewing any book. All zoom rates have been optimized providing high speed, dynamic screen display. An infinite hierarchy of folders can be created, moved, deleted, renamed, etc. using the enhanced bookshelf management function. Real visual bookshelf function that corresponds to back cover style display. Files can be imported by 3 methods, Network transfer through Dropbox, USB transfer through iTunes and direct transfer from other applications. Books can be protected so others cannot view them by using the password protected locking function. This is a universal application that operates on the iPhone, iPod Touch and iPad. =Functions= Overall: *Brightness Adjustment *Screen rotates to match the orientation of the device *Screen Rotation Lock *Password Protected Start-up Lock Viewer: *Support PDF,ZIP,CBZ,RAR and CBR format *Page Turning: Choose from slide or curl *Viewing Directions: Choose from opening left to right / right to left / vertically *Page Spacing: Choose form wide / narrow / none *Facing Pages: Choose the pair of facing pages by setting the cover to on or off *Trim function within the range of page display *Cache pre-read function for the previous and next pages *Set the display for each book and remember the page number of the last page read *Text search function (list display type) *Contents function (also supports hierarchy type) *Bookmark function (with editable memos) *Edit handwritten notes *Send to other applications (Open-In) *Send by email *Printing function (Air Print) *In-page link function *Link to outside URL function (built-in browser / Safari / Printing) *Display / Don't Display link buttons *Page turning function using tap or swipe *Expansion / Contraction function using pinch and double tap (1-1024x zoom) *Viewing of encrypted PDF files with password protection *Display / non-display of statusbar when reading Bookshelf: *Display form: Choose form list bookshelf / visual bookshelf *Function to set theme of visual bookshelf with each folder *Bookshelf thema extension pack (Add-On) *Cover editing function (corresponds to the trim) *File editing function: create, move, delete, setting for all books in folder *Bookmark list *Reading history list *Unread list *Edit of mark choose form already read / unread *Book name search function *Network transfer through Dropbox *USB transfer through iTunes *Direct transfer from other applications Special thanks to, "Give My Regards to Black Jack" SHUHO SATO Manga on Web http://mangaonweb.com
Flippy
This app transforms digital books into interactive reading experiences. Enjoy realistic page turns, listen to any book with natural voices, and get AI-powered explanations for complex content. It also offers study tools like flashcards and quizzes.
- Realistic page flipping animation
- AI-powered text-to-speech for any book
- AI explanations and Q&A
- Flashcards and quizzes from book content
- Automatic table of contents generation
- Offline reading and listening
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Flippy turns your PDFs and EPUBs — even scanned books, manga and comics — into real, flippable books: pages curl under your finger, a natural voice reads every page aloud, and built-in AI explains anything you don't understand. REALISTIC PAGE FLIP Swipe anywhere and watch pages curl, fold and settle with real physics. Tap the edges to turn, or glide with the chapter scrubber. On iPad, two-page book mode turns pages over the spine like a real book, and on iPhone Duo the spine sits right on the fold. SCANNED BOOKS, NOW READABLE A PDF that is just pictures of pages — an old textbook, a scanned manga? Flippy recognizes the text on your device, so Read Aloud, selection, Define, AI and Contents work like on any other PDF. Latin-alphabet languages, Chinese, Japanese, Korean, Hindi, Arabic and Russian. LISTEN TO ANY BOOK (Premium) Any PDF or EPUB becomes an audiobook. 8 natural voices read in the language of the text. Lock-screen controls, screen-off listening, speed from 0.75x to 2x. Highlight while you listen; tap the chip to return to the voice. Page numbers and repeated headers are skipped. Hearing the words while you see them helps readers with dyslexia, low vision and ADHD. TAKE IT WITH YOU Download a chapter — or just the pages you pick — and listen offline like a podcast. Saved it in another voice? Flippy tells you and switches in a tap. UNDERSTAND ANYTHING (Premium) Highlight a confusing passage and tap the glowing orb for a clear explanation, right on the page. Ask about your book — or another book in your library, with page citations. The AI can see the page, too: ask about a chart, figure, table or comic panel, even one on another page. Or ask out loud and hear the answer back. STUDY SMARTER Turn any chapter into flashcards or a practice quiz, save study sets, get chapter summaries. Define any word in any language, hear it pronounced, and keep it in My Words with the book it came from. IN YOUR LANGUAGE Flippy speaks 18 languages, now including Japanese, and follows your device language. Arabic and Farsi get a full right-to-left interface. AI answers in the language you read in. SMARTER CONTENTS Every PDF gets a tap-to-jump table of contents, even without one: Flippy finds the chapters by itself right after you open the book. A Bible lists its 66 books, a scanned course every lesson. Plus instant text search. FREE CLOUD SYNC Sign in with Google — free for everyone — and your bookmarks, highlights, notes, reading positions, collections and reading stats follow you across devices. Your PDF and EPUB files are never uploaded. READING FEATURES • Import from files, URLs or Google Drive links; Collections, a Continue Reading card, progress and streaks • Bookmarks with notes; multi-color highlighting, drawing and annotation • Scroll mode — continuous vertical reading • Fullscreen with pinch-to-zoom • Two-page spreads on iPad — beautiful for manga, comics and sheet music (Right-To-Left supported) • Pure-black interface, easy on your eyes and battery; works offline FREE & PREMIUM Reading, highlighting, bookmarking and cloud sync are free, and your first week unlocks every Premium feature — no card, no account. Premium then adds read-aloud, AI explanations and summaries, offline audio, every highlight color, extra bookmarks and note export. Pro suits heavy listeners; one-time packs like the Boost add minutes and AI uses, no subscription needed. PRIVACY FIRST No ads. No selling your data. Your files are never uploaded, and highlights and notes stay on your device unless you choose Cloud Sync — free, optional, deletable any time. Read Aloud sends only the text it reads; AI sends your question, the relevant page text and pictures of the pages involved, so it can read charts and figures. Details in our privacy policy. Download Flippy and rediscover the pleasure of turning pages. Terms of Use: https://flippypdf.github.io/terms-of-use/ Privacy Policy: https://flippypdf.github.io/privacy-policy/
Screenshots
Verdict
SideBooks and Flippy both sit at 4.7 stars, but that hides the real split: 74% of SideBooks's written reviews are positive against 0% of Flippy's. SideBooks also leads on ads (none vs shown) and ratings volume (98 vs 20). On price, rating, update cadence and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. SideBooks sells 1 one-off in-app purchase and Flippy sells 7 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.7 for SideBooks against 4.6 for Flippy. Both are backed by a comparable volume of ratings — 98 and 20 respectively. Written reviews are what separate them: 74% of SideBooks's written reviews are positive against 0% of Flippy's.
SideBooks ships an update every 9 days, Flippy weekly. The most recent releases landed on November 6, 2026 and November 5, 2026 respectively.
| Parameter | SideBooks | Flippy |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (98 ratings) — better | 4.6 (20 ratings) |
| Positive reviews | 73.8% of reviews — better | 0.0% of reviews |
| Number of ratings | 98 — better | 20 |
| Update frequency | Every 9 days | Weekly — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 15.0 — better | 15.1 |
| Further details — not scored | ||
| Size | 33 MB | 35 MB |
| Age rating | 4+ | 4+ |
| Developer | Tatsumi-system Co., Ltd. | Trison Braithwaite |
Customer experience
SideBooks
Flippy
Bugs and requests
SideBooks
Reported bugs
3 issues- Crashes when opening certain PDF files
- Corrupted files cause repeated crashes
- Dropbox integration issues on some devices
Requested features
6 requests- Add support for ePub and other popular formats
- Implement iCloud/Google Drive integration
- Allow manual rearrangement of bookshelf
- Add dark mode and customizable background options
- Improve bookmark and annotation features
Show 1 moreShow fewer
- Implement a more intuitive file management system
Flippy
Not enough reviews yet to summarise bugs or requests.
In-app purchases
SideBooks
- Thema extension Add-On$0.99
Flippy
- Flippy Premium Monthly$4.991 Month
- Flippy Pro Monthly$8.991 Month
- Flippy Premium Yearly$39.991 Year
Show 1 moreShow fewer
- Flippy Pro Yearly$69.991 Year
- Boost$2.99
- Plus$4.49
- Bulk$9.99









