Comparison

SynthBridge MIDI Synth vs spool.

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

Head to head
About

SynthBridge MIDI Synth

Transform your device into a versatile MIDI sound module and virtual piano. Load SoundFont files, connect controllers, and utilize expressive performance tools for practice, production, or live music.

Highlights
  • MIDI controller support (Bluetooth, USB, Network)
  • SoundFont (SF2/SF3) loading and playback
  • Multi-touch piano keyboard and drum pads
  • Pitch bend and modulation wheels
  • MIDI file playback and recording
  • Customizable velocity curves
Features
Read full description

Connect your MIDI keyboard, choose a sound, and play. SynthBridge turns your phone or tablet into a portable sound module and practice workspace. You can also start with the on-screen piano and drum pads. Your sounds: use the built-in library or import SF2/SF3 SoundFonts. Layer sounds and adjust their balance, effects and keyboard ranges. Your keyboard: connect compatible USB MIDI or Bluetooth MIDI devices. Control supported parameters with MIDI CC messages. Your practice: play MIDI files, follow the note visualization, and combine a metronome, loops and Style accompaniment. Your ideas: record MIDI performances, keep named drafts, preview takes and export MIDI files. MIDI files can also be converted to WAV or AAC audio. Your setup: save performance scenes and return to your sounds and playing settings. Use portrait or landscape layouts on phones and tablets. Some features and resources require in-app purchases. iOS or iPadOS 15.0 or later. USB and Bluetooth MIDI require compatible devices and accessories. https://synth.64bit.us/privacy.html https://synth.64bit.us/terms.html

About

spool.

Create full songs on your phone with this pocket music studio. It offers a variety of sound engines, sampling capabilities, step sequencing, and a 4-track tape recorder for recording and mixing your music. Effects and MIDI controller support enhance the creative process.

Highlights
  • Multiple sound engines
  • Sampling and sequencing
  • 4-track tape recording
  • Extensive effects rack
  • MIDI controller support
  • Step sequencer
Features
Read full description

Make a whole song on your phone. Spool is a pocket music studio inspired by the joy of hardware grooveboxes — play, sample, sequence, and record to tape, all in one playful instrument. Fourteen sound engines. From punchy FM and fat subtractive Pulse to shimmering Cluster, plucked String, granular Cloud, the TALK vocoder, the WIDE stereo engine, THUMP bass, a Sampler, and two drum machines — each with its own animated, touchable visualizer and four hands-on controls. Sample anything. Record straight from the mic into the sampler or drum kits, trim it, and play it across the keyboard. Drums & beats. Build kits, chop a sample into a playable kit, and lock in grooves with the step sequencer. Playful sequencers. Pattern and arpeggiator to start; unlock Stream, Taps, and the bouncing-ball Gumball machine for happy accidents. Six minutes of 4-track tape. Record, overdub, varispeed (including reverse), scrub, and bounce your jam to a finished mixdown — export to WAV. Your tape is saved with your project. Effects & mixer. A deep rack — delay, spring reverb, drive, compressor, chorus, multimode filter, phaser, tremolo/auto-pan, beat-repeat stutter, and a pitch-shifter/harmonizer — many tempo-syncable. Plus a master EQ and brickwall limiter so it always sounds finished. Plays with your gear. Connect a USB or Bluetooth MIDI controller and play Spool like hardware. AUv3 plugin support is planned for a future update. Free to download and make music with a starter set of engines and sequencers. A single one-time Spool Pro purchase unlocks the full instrument — all engines, sampling, every effect and sequencer, unlimited projects, export, and MIDI. No subscription. Spool is an original, independent work by a solo developer — affiliated with no hardware maker.

Screenshots

SynthBridge MIDI Synth4 screens
spool.4 screens

Verdict

The call

The clearest difference is rating: spool. at 5.0 against SynthBridge MIDI Synth's 4.7. spool. also leads on ratings volume (9 vs 3). SynthBridge MIDI Synth's advantage is iOS requirement (15.0 vs 17.0). On price, review sentiment, ads and in-app purchases 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. SynthBridge MIDI Synth sells 7 in-app purchases, starting at $1.99 per month and spool. sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

spool. holds the better App Store score, 5.0 against 4.7. Both are backed by a comparable volume of ratings — 3 and 9 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Scorecard3 real differences · 7 level
SynthBridge MIDI Synth versus spool.: the parameters behind the verdict, then further details
ParameterSynthBridge MIDI Synthspool.
PriceFreeFree
Rating4.7 (3 ratings)5.0 (9 ratings) — better
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings39 — better
Update frequencyEvery 11 days—
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better17.0
Further details — not scored
Size76 MB2 MB
Age rating4+4+
Developer啟东 徐Kristopher Yang

Customer experience

SynthBridge MIDI Synth

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

spool.

All ratings9 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

7 purchases

SynthBridge MIDI Synth

Subscriptions2
  • Cloud Monthly7 Days trial$1.991 Month
  • Cloud Yearly7 Days trial$12.991 Year
One-time5
  • Supporter Tip$0.99
  • Remove Ads$1.99
  • Supporter Plus$4.99
Show 2 more
  • SynthBridge Pro$4.99
  • Supporter Patron$9.99
1 purchases

spool.

One-time1
  • Spool Pro$9.99

Questions

Is SynthBridge MIDI Synth free?
SynthBridge MIDI Synth is free to download, with in-app purchases available.
Is spool. free?
spool. is free to download, with in-app purchases available.
Which has better reviews, SynthBridge MIDI Synth or spool.?
spool. is rated higher. SynthBridge MIDI Synth averages 4.7 out of 5 from 3 ratings, while spool. averages 5.0 from 9 ratings.
Do SynthBridge MIDI Synth or spool. have ads?
Neither SynthBridge MIDI Synth nor spool. shows ads.

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