RasterFX vs SLAP
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RasterFX
This app is a playable modular multi-effects processor for music creation. It allows users to build complex audio effect chains, modulate any control with various sources, and perform patches live. Visualizers provide real-time feedback on sound changes.
- Modular multi-effects processor
- Build custom effect chains
- Modulate any control
- Live performance features
- Real-time visualizers
- Record and share audio
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Make any sound move. RasterFX is a playable modular multi-effects processor for iPhone and iPad. Use it standalone with a microphone, an imported audio file or built-in signals — or load it as an AUv3 audio effect in AUM, GarageBand, Logic Pro for iPad, Loopy Pro, Cubasis and other Audio Unit hosts. BUILD YOUR EFFECT CHAIN Choose from Filter, Delay, Drive, Reverb, Grain, Repeat, Motion and Dynamics. Arrange up to six plates in series or split them into parallel A/B paths. Reorder the chain and the sound changes with it. MODULATE ANY CONTROL Patch LFOs, envelope followers, random and chaos sources, step sequencers, MIDI, macros, the XY pad or device tilt to any control. Create up to 16 modulation lines, with live arcs showing exactly how the sound is moving. PERFORM THE PATCH Morph between four snapshots on the XY pad. Turn eight macros. Hold four momentary throws for stutter, sweep, reverse and freeze. RasterFX is built to be played with one hand, not programmed and left alone. GENERATE, LOCK, EVOLVE Nudge a patch, reshape it or roll a new one. Lock the parts you want to keep, undo any result and save the seeds worth returning to. Evolve lets the patch drift over time while staying anchored to the sound you chose. SEE WHAT YOU HEAR Every effect has its own live visualizer. The CRT and halftone interface makes filters, delay taps, grains, dynamics and modulation visible without turning the screen into a wall of meters. RECORD THE RESULT Record the processed output to WAV, rename takes and share them from the app. FREE TO START. PRO ONCE. Free includes all eight effects, all modulation sources, every factory preset, three plates, four modulation lines and 60-second recordings. No ads, account, watermark or reduced audio quality. RasterFX Pro is a one-time purchase — not a subscription. It unlocks six plates, 16 modulation lines, split routing, XY snapshot morphing, Evolve, A/B compare, unlimited recording length and your own saved presets. Your saved sound always plays back exactly as created, even if it uses Pro features; Free limits editing, never playback. Made for headphones, late at night.
SLAP
Capture everyday sounds and transform them into music. Record, trim, and arrange your own audio samples on responsive pads to create unique beats and songs. Unlock advanced features and unlimited kits through in-app purchases or by watching rewarded ads.
- Record and import audio samples
- Non-destructive sample trimming
- Adjust sample volume, pitch, and speed
- Create and arrange patterns into songs
- Nine responsive playable pads
- Export and import custom kits
- Apply audio effects with Pro version
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Your world is full of sounds. SLAP turns them into beats. Record a clap, tap a desk, snap a pencil, or capture something wonderfully weird. Drop each sound onto a colorful pad, trim it until it hits just right, and start playing. SLAP stands for Sample, Loop, Arrange, Play—a focused beat-making flow that stays fun instead of feeling like homework. MAKE IT YOURS • Record sounds with your iPhone microphone • Import audio you already have • Trim samples non-destructively with detailed waveform controls • Adjust volume, pitch, and speed • Choose whether repeated hits restart or overlap • Name and customize every pad BUILD A BEAT • Play nine responsive pads • Capture taps into simple one-bar patterns • Switch between four patterns • Arrange patterns into an eight-bar song • Record a live performance or export your arranged song • Export and import kits to share them START FAST, THEN GET WEIRD Factory kits give you a quick starting point, but SLAP is built around sounds that are yours. Create three custom kits free, then watch optional rewarded ads to unlock up to three additional kit slots. GO FURTHER WITH SLAP PRO Unlock SLAP Pro with one purchase—no subscription. • Create unlimited custom kits • Save and reuse favorites with Your Sounds • Chop one recording of up to 30 seconds into an entire kit • Shape pads with Echo, Space, Crush, Wobble, Tone, and Reverse effects No account required. Your samples, kits, songs, and recordings stay on your iPhone unless you choose to export or share them.
Screenshots
Verdict
The clearest difference is ads: RasterFX at none against SLAP's shown. SLAP's advantage is ratings volume (8 vs 1). On price, rating, 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
Both are free to download. RasterFX sells 1 one-off in-app purchase and SLAP sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 5.0 for RasterFX against 5.0 for SLAP. That said, the two scores are not equally well evidenced: SLAP has 8 ratings behind it against 1, so its average is the more settled of the two.
| Parameter | RasterFX | SLAP |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (8 ratings) |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 1 | 8 — better |
| Update frequency | — | Weekly |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Freemium | Free with in-app purchases |
| Devices | iPhone, iPad — better | iPhone |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 5 MB | 27 MB |
| Age rating | 4+ | 4+ |
| Developer | Chih Han Lin | PATRICK H WALKER |
Customer experience
RasterFX
SLAP
In-app purchases
RasterFX
- RasterFX Pro$3.99
SLAP
- SLAP Pro$1.99









