Comparison

Klaus vs CPianoS

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

Head to head
About

Klaus

Features
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Mit der App für Klaus - Die Hackbrett Maus stimmst du dein Hackbrett schnell und präzise. Die App erkennt die Tonhöhe in Echtzeit und unterstützt dich beim genauen Stimmen deiner Saiten – einfach, übersichtlich und speziell fürs Käsehackbrett entwickelt.

About

CPianoS

Features
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Learning piano on your own? Photograph printed sheet music and the app reads it on your device (no account, no upload). See note names, hear them read aloud, or listen on a piano. IMPORT YOUR MUSIC - Scan with the camera (perspective correction, multiple pages), or pick from Photos or Files (PDFs, images) - Printed piano scores (grand staff) become playable music on your device - The printed tempo is read too (M.M. = 120, Allegro, rit., accel.) - Premium's latest recognition model also reads dynamics, hairpins, and pedal marks; pick the previous version in Settings - Re-read earlier scores by touching and holding them in the Library (the latest model needs Premium) REVIEW AND FIX THE RESULTS - Turn on Settings → Review recognition results to check uncertain notes one by one beside the image - Fix pitches and durations, add or remove notes, and finish your review later - After importing, fix notes, rests, chords, measures, key, time signature, dynamics, pedal, and tempo changes per measure in Edit - Tap the original image for full screen, zoomed in on the selected note READ MUSIC FASTER - Note names on every note (C D E, Do Re Mi, or Japanese note names) - Read aloud with a different voice for each hand; chords from the lowest note up - Choose voices, speech speed, and app language (20 languages) in Settings HEAR HOW IT GOES - Start at the score's own tempo (100%), then slow down or speed up, with dynamics, pedal, and tempo changes (rit., accel.) - Sounds: built-in upright, or download a grand piano. Concert grand piano with Premium - Play one hand only, loop A to B (saved per score), and follow along on the score COMPARE WITH YOUR PLAYING - Play a video of your playing (keys and hands) beside the score, including ones from Photos - Match one spot to the score, and the score follows the video, with the score's sound if you like - Videos are stored only on this device LIBRARY AND PRACTICE TIME - Scores on a bookshelf with covers; search by title and sort. Resume where you left off from Home - Time your practice; the timer shows on the Lock Screen and in the Dynamic Island - Add time manually; look back with weekly, monthly, and yearly charts by score FREE TO USE, WITH ADS - CPianoS is free, with ads in the Library and on the Import screen - 1 in 5 times you open a score, a short ad appears that you can close right away - Import up to 3 pages at a time without ads; from the 4th page, each ad you watch reads 2 more pages (internet required) PREMIUM (AUTO-RENEWING SUBSCRIPTION) - No ads at all, unlimited pages per import, and unlimited saved loops, plus the latest recognition model and the concert grand piano sound - Monthly and yearly plans. Prices are shown on the in-app purchase page - Payment is charged to your Apple ID when you confirm the purchase. It renews automatically unless canceled at least 24 hours before the current period ends - Manage or cancel in iPhone Settings → your Apple ID → Subscriptions - Terms of Use: https://giorrr.github.io/cpianos/terms_en.html - Privacy Policy: https://giorrr.github.io/cpianos/privacy_en.html PRIVACY - No account required - Score images, recognition results, practice history, and performance videos stay on your device and are never sent to the developer - Recognition and read-aloud run on your device - Premium shows no ads. Ads come from Google AdMob, which may use device identifiers and your interactions with ads. Your advertising identifier is used only if you allow tracking; every feature works either way - In the EEA, the UK, and some other regions, change your ad consent anytime in Settings → Privacy Settings GOOD TO KNOW - Only printed piano scores (grand staff) are supported, not handwriting or other instruments - Notes may be misread depending on print quality, lighting, and complexity. Review and fix them before you practice - Use imported scores for your own practice and respect the copyright of sheet music - Read-aloud uses the voices installed on your device

Screenshots

Klaus3 screens
CPianoS4 screens

Verdict

The call

The clearest difference is in-app purchases: Klaus at none against CPianoS's 2. Klaus also leads on ads (none vs shown) and iOS requirement (12.0 vs 26.0). CPianoS's advantage is update cadence (every 3 days vs monthly). On price and device support 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. CPianoS sells 2 in-app purchases, starting at $5.49 per month. Klaus asks for nothing beyond the download.

UpkeepUpdate frequency

Klaus ships an update monthly, CPianoS every 3 days. The most recent releases landed on November 5, 2026 and November 10, 2026 respectively.

Scorecard4 real differences · 2 level
Klaus versus CPianoS: the parameters behind the verdict, then further details
ParameterKlausCPianoS
PriceFreeFree
Update frequencyMonthlyEvery 3 days — better
AdsNo — betterYes
In-app purchasesNo — betterYes
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS12.0 — better26.0
Further details — not scored
Size32 MB118 MB
Age rating4+4+
DeveloperMarkus StradnerMiyauchi Isao

In-app purchases

None

Klaus

No in-app purchases

2 purchases

CPianoS

Subscriptions2
  • Premium (Monthly)$5.491 Month
  • Premium (Yearly)$46.991 Year

Questions

Is Klaus free?
Klaus is free to download, with no in-app purchases.
Is CPianoS free?
CPianoS is free to download, with in-app purchases available.
Do Klaus or CPianoS have ads?
CPianoS shows ads; Klaus does not.
Which is updated more often, Klaus or CPianoS?
Klaus ships an update monthly, and CPianoS every 3 days. Most recently, Klaus was updated on November 5, 2026 and CPianoS on November 10, 2026.

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