Comparison

Grasswhistle vs apeCsound

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

Head to head
About

Grasswhistle

Create unique melodies from chord progressions with a customizable arpeggiator. Offers randomization, performance options, and over 50 presets. Use it as a standalone instrument or a MIDI effect to sequence other devices.

Highlights
  • Customizable arpeggios
  • Chord progression sequencing
  • Randomization features
  • Performance options
  • 50+ factory presets
  • Standalone instrument
  • MIDI effect
Features
Read full description

Customizable arpeggios, right at your fingertips. Grasswhistle is a free arpeggiator from Aqeel Aadam Sound. Build a sequence of notes to arpeggiate your chord progressions in brand new ways. Grasswhistle adapts to whatever chord you throw at it, creating a seamless and recognizable melody from any chord progression. Find instant inspiration with robust randomization features, performance options, and 50+ factory presets. Grasswhistle can be loaded as an instrument or as a MIDI effect. As an instrument, it has a built-in synth voice for quick and easy playback. As a MIDI effect, you can sequence your favorite devices with endlessly inspiring arpeggios. Grasswhistle is completely free, though you can choose to send a tip inside of the standalone app. This is completely optional, but always appreciated! This donation does not unlock any additional functionality. Also available for macOS and Windows in VST3 / AU / AAX formats from Aqeel Aadam Sound.

About

apeCsound

Features
Read full description

apeCsound brings the full power of Csound 7, one of the most complete sound synthesis and signal processing languages ever created, inside your music apps. Write or paste any Csound orchestra, press Apply, and apeCsound turns it into an Audio Unit (AUv3) instrument or effect you can play, record and automate in GarageBand, Logic Pro for iPad, AUM, Cubasis, Loopy Pro and any other AUv3 host. It also runs as a standalone app. THE CSOUND ENGINE, BUILT IN Csound 7 is embedded in the app: nothing else to install Thousands of opcodes: oscillators, filters, physical models, granular, spectral (pvs), FM, waveguides, reverbs, delays, OSC and much more Process live audio from the host as an effect, or play it as a MIDI instrument Audio channels follow the host layout automatically Host transport available to your code as control channels: tempo, play/stop, position, time signature PARAMETERS YOUR HOST CAN AUTOMATE Describe sliders, switches, menus and XY pads directly in your .csd file apeCsound builds the control panel for you and exposes every parameter (176 in all) to the host for automation and MIDI learn Values are read in Csound with a simple chnget; chnset writes them back and moves the controls Organise the panel in collapsible groups with a comment in the code Snapshots: save, recall, rename and overwrite complete sets of values, stored with the session Undo and redo for every change, with one shared history LIVE CODING Evaluate sends the selection, the current instrument block or a single line to the running engine, without recompiling: redefine an instrument while it plays, change a global value, trigger a score event A dedicated Evaluate line for one-liners such as "i 2 0 1" SEE WHAT YOUR CODE IS DOING Monitor: every value written with chnset appears as a meter, a multi-bar card or a text line, with dB scale and history on request Channels: a diagnostic list of every channel the engine knows, with type, direction, value and who writes it; channels that nobody writes are flagged and can be mapped to a parameter in one tap Graphs: function tables and display signals drawn live, redrawn whenever a table changes Console: all Csound messages and errors, with errors marked on the line in the editor A CODE EDITOR MADE FOR CSOUND Syntax highlighting with dark and light themes, line numbers and adjustable text size Opcode completion that inserts the complete syntax, with outputs and optional arguments, in classic or modern (functional) style Jump between arguments with Tab Inline help bar showing the syntax of the opcode under the cursor, or the error on that line Find and replace, comment/uncomment, smart indentation Designed for touch: native-style selection handles, magnifier, edit menu and long-press caret navigation Built-in link to the Csound reference manual SESSIONS AND FILES Open and save standard .csd files from Files, iCloud Drive or any document provider Your code, parameters and snapshots are saved with the host project Start from a ready-made template, a blank session or one of nearly 200 included examples Import Cabbage and CsoundQt files: their widgets become parameters, their meters and displays show up in the Monitor ACCESSIBILITY Fully usable with VoiceOver: named controls, real menus, an accessible code editor and XY pad, complete keyboard navigation Whether you are a sound designer, a composer, a teacher or a student, apeCsound turns your iPad and iPhone into a complete Csound workstation that lives inside your favourite music apps.

Screenshots

Grasswhistle2 screens

Verdict

The call

The clearest difference is in-app purchases: apeCsound at none against Grasswhistle's 2. Grasswhistle's advantage is device support (3 vs 1) and iOS requirement (13.0 vs 17). On price, update cadence and ads 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. Grasswhistle sells 2 one-off in-app purchases. apeCsound asks for nothing beyond the download.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 days. The most recent releases landed on November 15, 2026 and November 10, 2026 respectively.

Scorecard3 real differences · 7 level
Grasswhistle versus apeCsound: the parameters behind the verdict, then further details
ParameterGrasswhistleapeCsound
PriceFreeFree
Rating5.0 (3 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings3 — better—
Update frequencyEvery 2 daysEvery 2 days
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree—
DevicesiPhone, iPad, iPod — betteriPad
Requires iOS13.0 — better17
Further details — not scored
Size18 MB33 MB
Age rating4+4+
DeveloperAqeel AadamapeSoft

In-app purchases

2 purchases

Grasswhistle

One-time2
  • Small coffee$3.00
  • Large coffee$5.00
None

apeCsound

No in-app purchases

Questions

Is Grasswhistle free?
Grasswhistle is free to download, with in-app purchases available.
Is apeCsound free?
apeCsound is free to download, with no in-app purchases.
Do Grasswhistle or apeCsound have ads?
Neither Grasswhistle nor apeCsound shows ads.
Which is updated more often, Grasswhistle or apeCsound?
Grasswhistle ships an update every 2 days, and apeCsound every 2 days. Most recently, Grasswhistle was updated on November 15, 2026 and apeCsound on November 10, 2026.

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