Uber Synth vs Stellr
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Uber Synth
This app offers a polyphonic multi-timbral FM synthesizer for iOS devices. It features a triple-oscillator sound engine with five distinct multi-timbral options for creating evolving and complex soundscapes. Supports Audiobus for integration with other music apps.
- Polyphonic multi-timbral FM synthesizer
- Triple-oscillator cross-modulated FM engine
- Five multi-timbral options
- Sound map and sound palettes
- Evolving sound generation
- Audiobus support
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Uber Synth is a polyphonic multi-timbral frequency modulated (FM) synthesizer that runs on any iOS device. The underlying sound engine is based on the triple-oscillator cross-modulated FM synthesizer first introduced in our xMod app. Uber Synth provides five multi-timbral options: 1) Mix the sounds of any two sound patches, 2) combine patches using the sound map, 3) Generate specified as well as randomized sound palettes across the keyboard, 4) Specify a region in sound space centered on a sound and move a point by a variable randomized amount within the region each time you play a note to create an evolving mix of the center sound and the sound nearest the point. 5) Do the same as above moving the point automatically at a specified rate. Supports Audiobus.
Stellr
Create deep, ethereal ambiance with a pitch-shifter, dual delays, and reverb. Explore sonic possibilities with 15 presets, randomization, and parameter automation. Enhance your music with a new dimension of sound.
- Pitch shifter with fine-tuning or semitone snap
- Two independent delays for complex feedback
- LFO modulation and various reverb types
- Pre-gain and dry/wet level control
- Audio Unit Extension, Audiobus, Inter-App Audio support
- 15 built-in presets with import/export
- Realtime frequency spectrum visualizer
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Stellr is a pitch-shifter/delay/reverb sound processor aimed to recreate the classic shimmer effect. It makes deep ethereal ambiance on top of your sound, providing you with a wide variety of sonic possibilities. Add a new dimension to your music. The effect features 20 ready to use presets which can be shared between devices as well as randomize button for endless variations. When loaded as Audio Unit effect, all parameters can be automated via host app. Stellr main features: – Pitch shifter which can be fine-tuned or snapped to semitone – Two separate delays for creating a complex feedback effect – LFO modulation and different types of reverb – Set pre-gain and dry/wet levels – Audio Unit Extension support – 20 built-in presets – Low-pass and High-pass filters – Ability to save and randomize parameters – Import and export of user presets – Realtime frequency spectrum visualizer
Screenshots
Verdict
The clearest difference is rating: Stellr at 3.4 against Uber Synth's 2.0. Stellr also leads on review sentiment (67% vs 50%) and ratings volume (9 vs 1). Uber Synth's advantage is update cadence (every 3 months vs every 40 months) and price ($3.99 vs $4.99). On ads, in-app purchases, monetization model 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
Uber Synth costs $3.99 and Stellr $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Stellr holds the better App Store score, 3.4 against 2.0. That said, the two scores are not equally well evidenced: Stellr has 9 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 50% of Uber Synth's written reviews are positive against 67% of Stellr's.
Uber Synth ships an update every 3 months, Stellr every 40 months. The most recent releases landed on September 29, 2026 and October 2, 2026 respectively.
| Parameter | Uber Synth | Stellr |
|---|---|---|
| Price | $3.99 — better | $4.99 |
| Rating | 2.0 (1 ratings) | 3.4 (9 ratings) — better |
| Positive reviews | 50.0% of reviews | 66.7% of reviews — better |
| Number of ratings | 1 | 9 — better |
| Update frequency | Every 3 months — better | Every 40 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 14.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 7 MB | 26 MB |
| Age rating | 4+ | 4+ |
| Developer | Mark Carlotto | BACKPULLVER SOFTWARE LTD OOD |
Customer experience
Uber Synth
Stellr
In-app purchases
Uber Synth
No in-app purchases
Stellr
No in-app purchases









