AudioStretch Lite vs DJ Kartier
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
AudioStretch Lite
This app allows musicians to slow down, loop, and transpose music from audio or video files. It also enables capturing video directly with your phone's camera for transcription. Ideal for learning songs by ear or experimenting with sound.
- Slow down audio/video without pitch change
- Loop difficult sections
- Transpose music notes
- Import audio/video files
- Capture video with phone camera
- Live waveform scrubbing
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As a musician one of the most helpful tools you can have is the ability to slow-down, loop or auto-transpose the notes for a piece of music you are trying to learn. AudioStretch is the world’s first audio and video transcription tool. Now you can manipulate the pitch, speed and transcribe your tunes from both audio and video files; or by using your phone’s camera you can capture video directly into AudioStretch and transcribe it! FEATURES INCLUDE: Import audio or video files Capture video with your phone camera for transcription Change the speed of files without changing the pitch Listen to the individual notes as you drag the waveform Play audio and video at zero speed Transpose any music Loop difficult to learn sections With AudioStretch you get all of this in an incredibly responsive and easy-to-use app. Ideal for transcription, learning songs by ear, crazy sonic experimentation, or just listening to your music library in a new way. Note: This is the LITE edition of AudioStretch, which has a few feature limitations. To get all the features, without the limitations, consider buying the Full version. LIMITATIONS OF LITE VERSION: • Max song duration 3 minutes (full version 3 hours) • Speed range from -1.5x to 1.5x (full version -10x to +10x) • Pitch shift +/- 3 semitones (full version +/- 36 semitones) DETAILED FEATURES: • Load songs from your Music Library • Document Picker import/export option supports iCloud, OneDrive, and more • Open Dropbox files and email attachments via "Open In" • LiveScrub™ : listen as you drag/hold the waveform • Instant freeze to zero speed by double-tapping on speed display • Keyboard/spectrum feature for transcription • Super-fine speed/pitch adjustment via drag left-right on speed/pitch display • Flexible looping feature • No ads or in-app purchases If you run into any problems with AudioStretch or AudioStretch Lite, please contact support@audiostretch.com
DJ Kartier
Explore over 1,000 iconic sounds and create music with a full-screen piano or a connected MIDI keyboard. Learn piano with interactive lessons, collaborate with friends in crews, and share your creations with the world.
- 1,000+ iconic sounds
- Full-screen piano
- Kartier Studio for song creation
- Interactive piano lessons
- Social Crews for collaboration
- MIDI keyboard connectivity
- Customizable RGB key lighting
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The DJ Kartier app puts 1,000+ iconic sounds at your fingertips - famous leads, pianos, synths, brass, and drums inspired by chart-topping hits - all playable right on your phone or with the Kartier Piano MIDI Keyboard Browse by artist, song, or instrument, tap a sound, and play it on a full-screen piano. Every preset is sound-designed accurately, with pro controls so you can make it your own. WHAT YOU CAN DO • Play 1,000+ iconic sounds across genres • Make full songs with Kartier Studio • Post your songs to Creations and share them anywhere • Team up with friends in Crews: chat, play games, and climb the leaderboard together • Learn piano with interactive lessons • Play games, climb the leaderboards, and level up to new ranks • Use the built-in multi-touch piano • Connect your Kartier Piano via bluetooth for full playability • Watch animated video tutorials for hundreds of presets • Control your Kartier Piano's RGB key lighting - rainbow, custom colors, scale guide, and more MAKE SONGS WITH KARTIER STUDIO Build full songs and make your next hit. Layer your tracks, share, and collaborate. Easy and simple to start producing music! CREATIONS: YOUR MUSIC ON THE FEED Post your Kartier Studio songs to Creations, a feed of songs played as falling notes in your own note colors and background. Like, comment, follow your favorite players, and earn XP for posting. Download Creations as videos in Standard, HD, or HD Smooth and share them anywhere. Creations is for players 13 and up. CREWS: SQUAD UP Start a crew with your friends, chat, share your music, and challenge each other to Balls Battle, chess, checkers, cup pong, or pool right in the chat. Send animated stickers and emotes, give your crew its own look, and grow it as you rank up. YOUR KARTIER PROFILE Sign in to keep your lessons, XP, and Phonk Simulator progress on any device, show off your Creations, and claim a name that's yours alone. LEARN TO PLAY WITH INTERACTIVE PIANO LESSONS Follow falling notes across scales, chords, and classic melodies - from Ode to Joy to Canon in D - on your on-screen piano or a connected keyboard. Work through a step-by-step piano course, play chords with more than one finger, and get real-time Perfect/Good/Miss feedback and an accuracy score as you play. Turn any MIDI file or Creation into your own Custom Lesson for free. Start with free lessons, or unlock the full library with Premium. SAFE BY DESIGN Every message, title, and comment is filtered, anything can be reported, and players under 13 get a private mode with Parent controls. PREMIUM • Monthly, annual (save 50%), or one-time lifetime • Unlocks every sound and every lesson, with new sounds added regularly • Premium backgrounds, stickers, and crews MADE BY PRODUCER SUPPLY DJ Kartier is the mobile companion to the Kartier Piano - the fastest way to play the sounds you love, whether you're producing, beatmaking, or just jamming. — All sounds are original recordings inspired by various musical styles. Any artist or song references are descriptive only; no affiliation or endorsement is implied. Subscriptions auto-renew unless cancelled at least 24 hours before the end of the period. Manage or cancel anytime in your App Store account settings. Privacy Policy: https://producersupply.com/pages/dj-kartier-app-privacy-policy Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is in-app purchases: AudioStretch Lite at none against DJ Kartier's 3. AudioStretch Lite also leads on review sentiment (73% vs 47%) and iOS requirement (12.0 vs 16.0). DJ Kartier's advantage is update cadence (every 3 days vs every 3 months) and rating (4.5 vs 4.0). On price, ratings volume, ads 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
Both are free to download. DJ Kartier sells 3 in-app purchases, starting at $4.99 per month. AudioStretch Lite asks for nothing beyond the download.
DJ Kartier holds the better App Store score, 4.5 against 4.0. Both are backed by a comparable volume of ratings — 623 and 243 respectively. Written reviews complicate that: 73% of AudioStretch Lite's written reviews are positive against 47% of DJ Kartier's, so the app with the better star average is not the one people write more warmly about.
AudioStretch Lite ships an update every 3 months, DJ Kartier every 3 days. Both last shipped on November 10, 2026.
| Parameter | AudioStretch Lite | DJ Kartier |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (623 ratings) | 4.5 (243 ratings) — better |
| Positive reviews | 72.9% of reviews — better | 47.4% of reviews |
| Number of ratings | 623 — better | 243 |
| Update frequency | Every 3 months | Every 3 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Freemium |
| Best chart rank | — | #63 — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 12.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 18 MB | 172 MB |
| Age rating | 4+ | 9+ |
| Developer | Cognosonic Pte Ltd | Producer Supply LLC |
Customer experience
AudioStretch Lite
DJ Kartier
Bugs and requests
AudioStretch Lite
Reported bugs
3 issues- Audio stops working after a while
- Video disappears when trying to screen record
- Crashes when trying to export or share content
Requested features
3 requests- Add more editing tools and effects
- Improve loop management and save options
- Implement night mode and other visual customizations
DJ Kartier
Not enough reviews yet to summarise bugs or requests.
In-app purchases
AudioStretch Lite
No in-app purchases
DJ Kartier
- DJ Kartier Premium$4.991 Month
- DJ Kartier Premium (Annual)$29.991 Year
- DJ Kartier Premium (Lifetime)$79.99








