iOS Companion

The iOS Companion puts two things from your Mac on your phone: your projects, with their saved versions and comments, and your Sample Library. It reads small summaries the Mac publishes rather than the files themselves — never the full .gsp bundle, and never the original sample — so a project arrives as artwork, tempo, track counts and version previews, and a sample arrives as a waveform drawing of about 9 KB.

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Requirements

• iPhone or iPad running iOS / iPadOS 18.0 or later
• The same Apple ID as your Mac, with iCloud Drive enabled
• Gridshift on macOS saving projects into the shared Gridshift iCloud container
• At least one saved version with a bounce preview if you want instant playback from the project list

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Two tabs

The app opens on Projects, which is the app as it has always been — the covers, the mini player, and the full-screen player they grow into. The app is always dark, whatever the phone’s own appearance, and both tabs stand on the ground of what you are listening to: Projects on the playing project’s cover, blurred, and Samples on the chosen sample’s waveform, blurred. When the song or sample changes, the ground fades to the new one. Samples is the second tab: your sample library, read out of the same iCloud projection, opened collection by collection. There is no search tab. The Samples tab carries its own search field, and inside a collection the query stays inside it.

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Browse the project list

Projects are grouped into horizontal carousels by collection, plus an Unsorted section for anything not filed yet. Project collections are shared with the Mac and editable on either device: + in the toolbar makes one, and a collection’s own menu renames or deletes it — deleting the collection returns its projects to Unsorted and changes nothing about the projects themselves. Pull to refresh rescans iCloud. A scan that fails leaves the list you already have alone rather than replacing it with an error; the unavailable state appears only when there is nothing to show. Tap a project cover to control browsing playback: You can also drag a project card into a different collection to file it there — both platforms read and write the same catalog.

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Control playback from the mini player

The mini player appears at the bottom of the project list after you select a project. It shows the project’s artwork, its name, and either the elapsed and total time or — when no bounce of it is playing — its tempo. Below them runs the whole bounce as a waveform, the played part lit; tap anywhere in it to jump there. Everything the bar says is about the project it names, not about whatever is coming out of the speaker. The two come apart in one case: a project with nothing bounced yet cannot be played, so paging onto it in the full-screen player changes the cover and the bar while the last project plays on. Tap the artwork or the name in the mini player to expand into the full-screen player. Tap the project artwork in the list to pause, resume, or switch playback.

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Open the full-screen player

Expanding the mini player opens a full-screen player, drawn over the artwork’s own blur:

• the cover, with a sliver of the projects either side of it in the row you tapped
• the project’s name, and under it the version you are hearing and the tempo — tap that line to open the version list
• a Versions button beside the name, which opens the same panel
• a scrubber showing the bar and beat under the playhead
• back, play, forward, and repeat — the skip buttons name the version they land on, so the button that moves you to v3 reads v3. Once three seconds have played, back restarts the current version instead
• AirPlay, a Comment button, and Share, which hands on the bounce file itself

Drag the cover sideways to walk to the next project in the row without leaving the player. The music follows the cover: the project you left goes quiet and the new one’s newest bounce starts. Neighbors are fetched ahead of you, so a swipe usually sounds at once. Bounce previews download from iCloud on demand. While one is still being fetched the mini player reads Downloading…, and playback starts by itself once the file is local.

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Leave a comment while you listen

A comment left from the phone captures the exact playing position the moment you open the composer field — the version and the second within it — so it reads back as a specific moment in the music, not just a note. The Mac shows the same comment with a time chip naming that version and position. Comments without a captured position are notes about the project as a whole. Either kind can be checked off or deleted from either device.

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Browse the sample library

The Samples tab opens on your collections, laid out like the sidebar of the Mac’s Sample Library: All Samples, Unsorted and your audio collections first, then the same for MIDI patterns under Patterns. Each entry shows its count. Tap one to open its list. A collection’s list is where you decide what happens to a sample. At the bottom, where the mini player sits in Projects, runs one waveform: the sample you are on, drawn the way the editor draws it, with the playhead running while it sounds. The whole list stands on that sample’s blurred waveform in its collection’s color. Above it, each row is a small thumbnail with the name, the length or the pattern’s beats and notes, the tempo, and a star if you have favorited it.

• Tap a row to select it and hear it. The row lights up, and the waveform and the ground switch to it. Tap it again to stop.
• Tap the waveform to play from that point, so you can listen into the middle of a long loop.
• Starting one preview stops the last, though never the project bounce playing in the other tab.

Search matches names and tags and stays inside the collection you opened. Searching from the top level searches the whole library, with the same waveform over the results. Beside the field sits the filter button, which holds the sort: Name, Favorite, Length, Tempo, or Added, which puts the samples that came into your library most recently at the top. On iOS 26 both sit in the bottom bar, within reach of a thumb; on iOS 18 they are at the top right.

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What the phone downloads

A sample is auditioned from a small mono copy the Mac makes — the whole sample, at roughly 1.5 % of its size — never the original file. The rows just below the fold are fetched ahead of your thumb — eight of them, three at a time — and dropped again the moment you scroll past. The sample under the waveform and the rows around it are also opened ahead of your tap, so they start without a pause. The phone keeps 256 MB of auditioned audio and discards the least recently played beyond that.

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Curate from the phone

Four things travel back to the Mac: the favorite mark, your own tags, which collection a sample is in, and the Trash. Swipe a row left for Delete, with Favorite and Tag behind it; a full swipe deletes. Swipe right to file the sample into the collection you last used — the label names it, so a full swipe is never a surprise. Press and hold a row for the same choices by name, plus Tags…, a checklist that adds, removes and renames tags without closing after each one. When you delete, file or tag the sample under the waveform, the list moves on to the next row and plays it. Sorting a collection becomes listen, decide, listen. Favoriting does not move on, since marking a sample is often the reason to keep listening to it. To act on many samples at once, tap Select, pick rows, and use the bar that takes the search field’s place: Favorite, Collection, Tag, Delete. Deleting sends the sample to the Mac’s Trash and destroys nothing — the file, the favorite mark, the tags and the collections all survive, and Put Back on the Mac restores them for thirty days. There is no confirmation; an Undo bar appears instead. Deletions travel both ways, so a sample you trash on the Mac leaves this list too. Every edit is written down on the phone before anything is sent, so curating with no signal works and catches up the next time you open the tab. The phone only ever sends the fields you touched, so it can never overwrite something the Mac knows about a sample and the phone does not.

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Edit a sample

Edit on the waveform opens the sample’s editor at Slices, Tempo or Sampler. The waveform grows into the full screen, and a swipe back shrinks it into the list again. The editor is for cutting and shaping only. Sample holds the slice pads with Detect, Tempo and Shape; Sampler plays the sample as an instrument with Env, LFO, Loop and Sound. The chevrons next to the name step to the sample before or after it in the list, and the list follows you, so going back lands on the last sample you worked on. The ⓘ holds how the Mac plays the sample on a track, as slices or as an instrument, and the file’s format, length and key.

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Remove a project from a collection

Long-press a project card to open a context menu with an artwork preview. Inside a collection, choose Remove from [Collection] to unfile it — the project moves back to Unsorted, and nothing about the project itself changes.

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How iCloud storage works

The companion app is designed around iCloud-backed projects:

• the project list comes from the CloudKit projection the Mac publishes — a handful of small records, cached on the device — not a scan of the .gsp bundles themselves
• if CloudKit sync has never run for a given Mac, the companion falls back to scanning manifest.json directly out of the project bundles in iCloud Drive, and bundles saved before manifests existed fall back further, to project.json
• the sample library comes from a second zone of the same projection: one record per sample and one per collection, with the waveform drawing on the sample’s own record. Sample audio lives in a third zone, and only ever one small preview copy at a time
• version bounces download on demand when playback starts, and the projects either side of the one you are hearing are fetched ahead so a swipe of the cover strip sounds at once
• comment edits made on the phone are proposals: they sync as CloudKit records, but the Mac is the one that merges them into the shared list per comment by last-writer-wins and publishes the merged result back, so both devices converge on one order
• sample curation from the phone is not a proposal: it writes the four fields you touched straight onto the sample’s record, leaving every other field the Mac owns untouched

For more about the shared storage layout, see iCloud Integration.