Comparison

Sullivan+ vs Big Thumb Keyboard

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Sullivan+

This visual assistance app uses AI and your smartphone camera to describe surroundings, read text, identify faces, and find objects. It offers features like currency recognition and color identification to enhance accessibility for the blind and visually impaired.

Highlights
  • AI object and scene description
  • Text recognition and reading
  • Face recognition with age/gender
  • Object finder with voice guidance
  • Currency denomination announcement
  • Color recognition
Features
Read full description

Sullivan Plus is a visual assistance app provided by TUAT for information accessibility for the blind and low vision, and provides information recognized through the smartphone camera to users who need visual assistance. Sullivan Plus X SKtelecom Please support the warm collaboration between Sullivan Plus and SKtelecom! Experience Sullivan Plus with SKtelecom's diverse and powerful AI technologies! ■ AI Facecan that recognizes age, gender, and facial expressions Register your face The face registration function has been added to the face recognition mode. You can register the face of anyone you want, and find the face of the person you registered in a photo. Object Finder The object-finding feature has been added. Select the object you want to find from the list and scan your surroundings. The app will notify you with vibrations and voice prompts. PDF Quota Donation Donate your unused PDF Reader quota to help others who need it. By donating, users who have exhausted their PDF quota for the day will be able to read additional image-based PDF files based on the donated amount. If you’ve already used up your quota for the day, you can request donations. Other users can see your donation request message and choose to participate. :) Currency Recognition Sullivan Plus announces the denomination of bills via voice. (Supported currencies: Korean Won, US Dollar, Euro, Japanese Yen) Q&A Board The Q&A Board has been added for users who couldn’t resolve questions or share tips due to the lack of a communication space. If someone comments on your post, you’ll receive a notification so you can check it instantly! [Key Features] 1. AI Mode 2. Automatic Image Description 3. Text Recognition 4. Face Recognition ■ Curious about your surroundings? AI Mode - Identifies objects around you and generates descriptive sentences for the scene. ■ Struggling to read letters on mail, magazines, or newspapers? Text Recognition - Detects text and announces it audibly. Point your camera at the area with the text you want to recognize. ■ Wondering about someone you just met? Face Recognition - Identifies the person captured on camera and provides their age and gender. ■ Automatically recognize your surroundings. Automatic Image Description - No need to press the shutter button. The app automatically detects the environment and provides voice guidance. ■ Looking for the location of objects around you? Object Finder - Select the object you’re looking for, and the app will guide you to its location using voice prompts. ■ Having trouble finding the right color for your outfit in the morning? Color Recognition - Supports single-color mode to identify the color at the center of the screen and full-screen mode to identify dominant colors across the entire view. ■ Manage Samsung Electronics home appliances more smartly! Consumer Electronics Mode - Connect the QR code of Samsung Electronics home appliances to the SmartThings app to easily control products, check their status, access manuals, and request services. ■ Assisting those with low vision, not just total blindness. Magnifier - The camera's zoom function lets you enlarge or reduce objects or text and supports color inversion. [Permissions Required] The camera is used to capture images so the app can describe objects, text, and surroundings aloud for users who are blind or have low vision. Camera - Controls the camera and captures photos using the camera API. Storage - Temporarily stores captured images and deletes them after the analysis is complete. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Big Thumb Keyboard

This keyboard app uses a unique gesture-based system to allow typing with a single thumb. It offers features like an 8-way swipe system, consistent button size, one-handed mode, phonetic logic, and advanced autocorrect.

Highlights
  • 8-Way Swipe System
  • Consistent Button Size
  • True One-Handed Typing
  • Phonetic Hangul Logic
  • Pro-Grade Autocorrect
  • Haptic Feedback
  • Quick Symbols & Numbers
Features
Read full description

Tired of Typos? Meet the Keyboard Built for Your Thumb. Stop squinting at tiny keys and struggling with "fat finger" errors. Big Thumb Keyboard is a revolutionary, gesture-based typing system that lets you access every character (letters, numbers, and symbols) with a single thumb, without ever switching layouts. ONE PRICE. NO SUBSCRIPTIONS. NO ADS. In a world of monthly fees, we keep it simple: Pay once, type forever. No data collection. No tracking. Just a better way to type. WHY CHOOSE BIG THUMB? - The 8-Way Swipe System: Every button is a powerhouse. Swipe in any of 8 directions (up, down, corners, etc.) to instantly type different letters. It’s faster, more accurate, and feels like magic once you find your rhythm. - Perfect Muscle Memory: Unlike other keyboards that shrink or grow, our buttons stay a consistent 5mm wide on every device. Whether you’re on an iPhone SE or an iPad Pro, your thumb always knows exactly where to go. - True One-Handed Typing: Carrying a coffee? Holding a baby? Just swipe the Shift key to toggle One-Handed Mode and fly through your messages with ease. - Phonetic "Hangul" Logic: We’ve grouped letters by how they sound (Lips, Tongue, Throat). It’s a scientifically backed system that makes learning the layout surprisingly intuitive. - Pro-Grade Autocorrect: Advanced AI learns your patterns. Made a mistake? Our 2-second Instant Undo lets you revert a correction with one tap of the backspace. FEATURES YOU’LL LOVE - Haptic Feedback: Feel the "click" of every swipe. Distinct vibrations for different directions help you type without even looking at the screen. - Quick Symbols & Numbers: No more hunting through sub-menus. Access punctuation and math symbols instantly through control swipes. - Privacy First: We don't want your data. Your keystrokes stay on your device—period. Full Access is only required for haptic feedback and local settings. IS THIS FOR YOU? - Large Hands? Finally, keys you can actually hit. - Accessibility Needs? Designed for those who need high-precision, low-mobility input. - Efficiency Junkies? Master the swipe and outpace standard QWERTY typists. 30-SECOND SETUP - Install the app. - Go to Settings → General → Keyboard. - Tap Keyboards → Add New Keyboard → Big Thumb Keyboard. - (Optional) Allow Full Access to enable haptic feedback. Join the typing revolution. Download Big Thumb Keyboard today and take back your screen!

Screenshots

Sullivan+4 screens
Big Thumb Keyboard4 screens

Verdict

The call

The clearest difference is review sentiment: Sullivan+ at 86% against Big Thumb Keyboard's 0%. Sullivan+ also leads on price (Free vs $2.99) and rating (4.4 vs 1.0). Big Thumb Keyboard's advantage is in-app purchases (none vs 3). On ads, device support and iOS requirement 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

CostPrice · In-app purchases · Ads · Monetization

Sullivan+ is free to download; Big Thumb Keyboard costs $2.99 up front. Sullivan+ sells 3 in-app purchases, starting at $9.99 per month. Big Thumb Keyboard asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Sullivan+ holds the better App Store score, 4.4 against 1.0. That said, the two scores are not equally well evidenced: Sullivan+ has 22 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 86% of Sullivan+'s written reviews are positive against 0% of Big Thumb Keyboard's.

UpkeepUpdate frequency

Sullivan+ ships an update every 2 months, Big Thumb Keyboard every 6 months. The most recent releases landed on October 20, 2026 and October 9, 2026 respectively.

Scorecard7 real differences · 3 level
Sullivan+ versus Big Thumb Keyboard: the parameters behind the verdict, then further details
ParameterSullivan+Big Thumb Keyboard
PriceFree — better$2.99
Rating4.4 (22 ratings) — better1.0 (1 ratings)
Positive reviews85.7% of reviews — better0.0% of reviews
Number of ratings22 — better1
Update frequencyEvery 2 months — betterEvery 6 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree — betterPaid
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.6 — better18.5
Further details — not scored
Size136 MB44 MB
Age rating4+4+
DeveloperTUAT Inc.Bukdu Group, LLC

Customer experience

Sullivan+

All ratings22 ratings
Positive77.3%
Neutral18.2%
Negative4.5%
Written reviews35 reviews
Positive85.7%
Neutral14.3%
Negative0.0%

Big Thumb Keyboard

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

3 purchases

Sullivan+

Subscriptions1
  • Pro$9.991 Month
One-time2
  • Pro Usage 5,000 Top-Up$2.99
  • Pro Usage 15,000 Top-Up$6.99
None

Big Thumb Keyboard

No in-app purchases

Questions

Is Sullivan+ free?
Sullivan+ is free to download, with in-app purchases available.
Is Big Thumb Keyboard free?
Big Thumb Keyboard costs $2.99, with no in-app purchases.
Which has better reviews, Sullivan+ or Big Thumb Keyboard?
Sullivan+ is rated higher. Sullivan+ averages 4.4 out of 5 from 22 ratings, while Big Thumb Keyboard averages 1.0 from 1 ratings.
Do Sullivan+ or Big Thumb Keyboard have ads?
Neither Sullivan+ nor Big Thumb Keyboard shows ads.
Which is updated more often, Sullivan+ or Big Thumb Keyboard?
Sullivan+ ships an update every 2 months, and Big Thumb Keyboard every 6 months. Most recently, Sullivan+ was updated on October 20, 2026 and Big Thumb Keyboard on October 9, 2026.

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