Comparison

Stellr vs Phosphor 3

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

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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

About

Phosphor 3

This app recreates a vintage digital synthesizer, offering a faithful emulation of a classic sound engine. It includes modern features like MPE, extensive modulation, and a new UI for sonic exploration.

Highlights
  • Vintage digital synthesizer emulation
  • Additive synthesis engine
  • MPE support
  • Extensive modulation routing
  • Preset manager
  • Tuning tables
Read full description

Glow in the dark synthesis. Phosphor 3 is a dual-oscillator additive synthesizer that puts the raw building blocks of sound at your fingertips. Draw, randomize, or select up to 64 harmonics per oscillator, then shape them with envelopes, LFOs, cross-modulation, and a flexible mod matrix. Originally inspired by the alphaSyntauri, a rare digital additive synth from the early 1980s, Phosphor 3 takes that concept far beyond its origins with modern MPE expression, polyphonic modulation, and a full effects engine. --- Additive Oscillators Two identical additive oscillators, each with up to 64 individually editable harmonics. Start from classic shapes: sawtooth, triangle, square, or draw your own harmonic spectrum directly in the partial editor. The intelligent randomizer generates musically useful timbres with variable rolloff, density, and formant peaks, so every click produces something worth exploring. Choose 16, 32, or 64 partials per oscillator to balance complexity against CPU. Each oscillator has independent level, pan, transpose, fine tune, a noise generator with lo-fi downsampling, and cross-modulation (FM) for pushing timbres into harsher, more complex territory. Modulation Two ADSR envelopes with adjustable attack, decay, and release curves. Two LFOs with four waveforms (pulse, sine, saw, random), tempo sync, and the option to run polyphonically, a separate LFO per voice, or globally. An 8-source modulation matrix routes velocity, pressure, pitch bend, mod wheel, CC 74, triggered random, and both LFOs to destinations across the oscillators and effects. Effects Stereo delay with independent left/right time, feedback, and cross-channel feedback for ping-pong and rhythmic patterns. Tempo sync locks delay times to your DAW. Dual band-pass filters after the delay let you carve the wet signal into resonant, frequency-specific textures. Expression Full MPE support with per-note pitch bend, pressure, and slide across 16 polyphonic voices. Mono legato and mono retrigger modes with adjustable portamento. Unison mode for thick, detuned stacks. A scrollable 128-key on-screen keyboard with velocity from touch position, pitch bend from horizontal drag, and channel pressure from vertical drag, no hardware controller required. Tuning MTS-ESP client support for real-time microtuning from any MTS-ESP master. TUN file import for custom scales. Standard 12-TET with adjustable A4 reference. Supports AUv3 for use in GarageBand, AUM, Cubasis, and other AUv3-compatible hosts.

Screenshots

Stellr2 screens

Verdict

The call

The clearest difference is rating: Phosphor 3 at 4.7 against Stellr's 3.4. Phosphor 3 also leads on update cadence (every 11 months vs every 40 months) and review sentiment (79% vs 67%). Stellr's advantage is device support (3 vs 1) and price ($4.99 vs $5.99). On ratings volume, ads, in-app purchases and monetization model 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

Stellr costs $4.99 and Phosphor 3 $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Phosphor 3 holds the better App Store score, 4.7 against 3.4. Both are backed by a comparable volume of ratings — 9 and 9 respectively. Written reviews point the same way: 67% of Stellr's written reviews are positive against 79% of Phosphor 3's.

UpkeepUpdate frequency

Stellr ships an update every 40 months, Phosphor 3 every 11 months. The most recent releases landed on October 19, 2026 and October 24, 2026 respectively.

Scorecard5 real differences · 5 level
Stellr versus Phosphor 3: the parameters behind the verdict, then further details
ParameterStellrPhosphor 3
Price$4.99 — better$5.99
Rating3.4 (9 ratings)4.7 (9 ratings) — better
Positive reviews66.7% of reviews78.6% of reviews — better
Number of ratings99
Update frequencyEvery 40 monthsEvery 11 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPod — betteriPad
Requires iOS12.012.0
Further details — not scored
Size26 MB27 MB
Age rating4+4+
DeveloperBACKPULLVER SOFTWARE LTD OODAudio Damage, Inc.

Customer experience

Stellr

All ratings9 ratings
Positive55.6%
Neutral11.1%
Negative33.3%
Written reviews3 reviews
Positive66.7%
Neutral0.0%
Negative33.3%

Phosphor 3

All ratings7 ratings
Positive85.7%
Neutral14.3%
Negative0.0%
Written reviews14 reviews
Positive78.6%
Neutral14.3%
Negative7.1%

In-app purchases

None

Stellr

No in-app purchases

None

Phosphor 3

No in-app purchases

Questions

Is Stellr free?
Stellr costs $4.99, with no in-app purchases.
Is Phosphor 3 free?
Phosphor 3 costs $5.99, with no in-app purchases.
Which has better reviews, Stellr or Phosphor 3?
Phosphor 3 is rated higher. Stellr averages 3.4 out of 5 from 9 ratings, while Phosphor 3 averages 4.7 from 9 ratings.
Do Stellr or Phosphor 3 have ads?
Neither Stellr nor Phosphor 3 shows ads.
Which is updated more often, Stellr or Phosphor 3?
Stellr ships an update every 40 months, and Phosphor 3 every 11 months. Most recently, Stellr was updated on October 19, 2026 and Phosphor 3 on October 24, 2026.

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