Comparison

Tappi vs Unknown app

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

Head to head
About

Tappi

This companion app enhances interactive board books by bringing them to life with sound, music, and games. It allows parents to set up the associated play pen, download content, and configure audio settings for an enriched reading experience.

Highlights
  • Interactive book enhancement
  • Sound, music, and games
  • Parental setup for play pen
  • Content download
  • Audio configuration
Features
Read full description

This app is a companion app to Tappi, and is not meant to be used standalone. Tappi an interactive reading system that brings children's board books to life with sound. Using the Tappi Play Pen, tap anywhere in Tappi books to play stories, music, and games. The Tappi app allows parents to perform initial setup for the Tappi Play Pen, such as downloading content or configuring music settings.

About

Unknown app

Transform documents into audiobooks with a lifelike voice. Read along as text highlights in sync with narration. Sync your library across devices and even use your own voice for narration.

Highlights
  • PDF and EPUB narration
  • Lifelike voice narration
  • Synchronized text highlighting
  • Custom voice recording
  • Cross-device syncing
  • arXiv paper search
  • Mind map generation
Features
Read full description

Unknown turns dense reading into listening. Add a PDF, EPUB or paper and Unknown narrates it in a lifelike voice, lighting up every line on the real pages as it plays. YOUR OWN VOICE Read a few short passages aloud and Unknown narrates any document in your voice. Try it free for 5 minutes. Unknown Pro includes 1 free hour, and you can add 3, 6 or 12 more hours as one-time purchases. Your recordings stay on your device and go to our cloud only with documents narrated there, and are deleted as soon as each is ready. NO MAC NEEDED Add documents right on your iPhone or iPad: upload a file, paste a link, or share one from any app. Without a Mac, Unknown converts them in the cloud, up to 30 documents and 2,000 pages a month, 500 pages per document. With the Unknown app for Mac, documents are narrated privately on your Mac with no limits and appear here automatically. READ ALONG ON THE REAL PAGES The actual pages render on screen while the current paragraph lights up in sync with the audio. Swipe to a page and the audio follows. YOUR WHOLE LIBRARY, IN SYNC Progress, bookmarks, notes and mind maps sync through your account between your iPhone, iPad and Mac. Pause on the Mac, resume on your iPhone. FIND PAPERS ON ARXIV Search arXiv from the app and listen to any paper. MIND MAPS Maps generated on your Mac arrive with each document: the whole argument at a glance. WIDGETS AND SHORTCUTS Pick up where you left off from a Home Screen widget or a Control Center control. PRIVACY Documents your Mac narrates sync through your own iCloud, and no server of ours sees them. Documents converted in the cloud are sent over an encrypted connection, deleted after 7 days, never read by a person and never used to train AI. Voice recordings sent along for narration are deleted as soon as the document is ready. BUILT FOR LISTENING Background audio with lock screen controls, adjustable speed, 15 second skips, and paragraph by paragraph highlighting. SUBSCRIPTION Your first 2 documents are free, and a sample document is included. Unknown Pro unlocks the whole app with a weekly, monthly or yearly subscription; monthly and yearly start with a 7-day free trial for new subscribers. Payment is charged to your Apple ID when you confirm the purchase, or when the free trial ends. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period, and can be managed or cancelled in your App Store account settings. Unknown Pro also works in the Mac app and on unknown.ac. Voice hours for narrating in your own voice are one-time purchases that need an active subscription to use. Terms of Use: https://unknown.ac/terms.html Privacy Policy: https://unknown.ac/privacy.html

Screenshots

Tappi2 screens
Unknown app4 screens

Verdict

The call

The clearest difference is rating: Unknown app at 5.0 against Tappi's 2.4. Unknown app also leads on update cadence (every 4 days vs every 6 weeks). Tappi's advantage is in-app purchases (none vs 6) and ratings volume (5 vs 1). On price, 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

Both are free to download. Unknown app sells 6 in-app purchases, starting at $2.99 per 7 days. Tappi asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Unknown app holds the better App Store score, 5.0 against 2.4. That said, the two scores are not equally well evidenced: Tappi has 5 ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

Tappi ships an update every 6 weeks, Unknown app every 4 days. The most recent releases landed on November 5, 2026 and November 10, 2026 respectively.

Scorecard5 real differences · 4 level
Tappi versus Unknown app: the parameters behind the verdict, then further details
ParameterTappiUnknown app
PriceFreeFree
Rating2.4 (5 ratings)5.0 (1 ratings) — better
Number of ratings5 — better1
Update frequencyEvery 6 weeksEvery 4 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFreemium
DevicesiPhone, iPadiPhone, iPad
Requires iOS16.6 — better17.0
Further details — not scored
Size3 MB57 MB
Age rating4+4+
DeveloperYiwen ZhanVritam LP

In-app purchases

None

Tappi

No in-app purchases

6 purchases

Unknown app

Subscriptions3
  • Unknown Pro Weekly$2.997 Days
  • Unknown Pro Monthly7 Days trial$4.991 Month
  • Unknown Pro Yearly7 Days trial$49.991 Year
One-time3
  • 3 Hours in Your Voice$4.99
  • 6 Hours in Your Voice$9.99
  • 12 Hours in Your Voice$19.99

Questions

Is Tappi free?
Tappi is free to download, with no in-app purchases.
Is Unknown app free?
Unknown app is free to download, with in-app purchases available.
Which has better reviews, Tappi or Unknown app?
Unknown app is rated higher. Tappi averages 2.4 out of 5 from 5 ratings, while Unknown app averages 5.0 from 1 ratings.
Do Tappi or Unknown app have ads?
Neither Tappi nor Unknown app shows ads.
Which is updated more often, Tappi or Unknown app?
Tappi ships an update every 6 weeks, and Unknown app every 4 days. Most recently, Tappi was updated on November 5, 2026 and Unknown app on November 10, 2026.

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