Dropack

Big files. Shared in batches.

A native iPhone and iPad app for packaging original photos and videos, sharing them through the iOS share sheet, and saving received media to Photos with progress and recovery.

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What it does

• Share albums: select photos, videos, or files; manage an album; create its archive when sharing. Reuse unchanged packaged resources when updating an archive.
• Use AirDrop: send a .dropack package through Apple's system share sheet, or export a standard ZIP for other tools. A .dropack file is a ZIP archive with an album manifest.
• Receive safely: inspect a received album before saving. Import photos, videos, ZIPs, or folders chosen in Files, including supported external drives and cloud providers.
• See the work: distinguish iCloud downloads from packaging, show item progress, pause and resume supported tasks, and surface progress with Live Activities on supported devices.
• Avoid repeat imports: use content hashes and local import history to skip previously confirmed saves. Ambiguous interrupted saves require review rather than automatic duplication.
• Keep control: browse album media, add or remove album items, manage local packages, and choose the app language and appearance.

Dropack runs on iOS / iPadOS 17 or later and includes 16 languages. Processing happens on the device; there is no Dropack account or file-upload backend. iCloud, AirDrop, Files providers, and update checks can use the network.

Build

You need a Mac, Xcode 26 or later (the source uses the iOS 26 background-processing APIs behind availability checks), and Python 3 for project/resource maintenance. The app itself is Swift / SwiftUI; Expo and Node.js are not required to build it.

git clone https://github.com/chekusu/dropack.git
cd dropack
open Dropack.xcodeproj

Choose the Dropack scheme and an iPhone or iPad simulator. Xcode resolves ZIPFoundation 0.9.20, pinned in the project and integration-test package.

For a device build, use your own Apple development team. Forks must choose their own app and Live Activity extension bundle identifiers. If you change the app.dropack.ios prefix, update the background-task identifiers in PhotoRelay/Info.plist and PhotoRelay/Services/PackageBackgroundExecution.swift as well. The project generator contains the bundle-ID defaults; update it before regenerating the project. No signing certificates, provisioning profiles, Apple credentials, or official Expo release configuration are included.

An unsigned simulator build:

xcodebuild -project Dropack.xcodeproj -scheme Dropack \
  -destination 'generic/platform=iOS Simulator' \
  -derivedDataPath build/DerivedData CODE_SIGNING_ALLOWED=NO build

Development and checks

python3 scripts/generate_project.py --check
python3 scripts/localization_audit.py
python3 -m unittest discover -s scripts/tests
swift test --build-system native
swift test --build-system native --package-path Tests/ZIPIntegration

After adding Swift files, run python3 scripts/generate_project.py. After changing translations, run python3 scripts/localization_audit.py --write and regenerate the project. See localization notes.

Directory	Contents
PhotoRelay/Core	Album models, checkpoints, ZIP validation, resumable file copying, and import identity
PhotoRelay/Services	PhotoKit, file access, packaging/import workers, previews, and background execution
PhotoRelay/UI	SwiftUI screens and native UIKit presentations
Shared, DropackLiveActivity	ActivityKit data and the Live Activity extension
Tests	Core, ZIP interoperability, app integration, and UI tests
localization	Translation sources for 16 languages

PhotoRelay is the original source-directory name. The product is Dropack. ZIP test fixtures are generated from synthetic data by Tests/ZIPIntegration/generate_fixtures.py.

Boundaries

• AirDrop controls network transfer and receiving behavior. Dropack does not implement a cross-platform transport or byte-level AirDrop resume. iOS may open received files in Files before the user chooses Dropack.
• Packaging preserves original media without transcoding. Original metadata, including location when present, can travel with the package.
• Packaging/ZIP recovery uses item checkpoints; interrupted items can need reprocessing. Direct-file staging can resume by byte offset, while a Photos save must complete as a whole item.
• Background execution is granted by iOS. Live Activities alone do not keep the app running; the app pauses safely when its execution time expires.
• Imports require available device storage. Cloud providers may download an archive before Dropack can inspect it. Media codec support depends on iOS.
• Encrypted, split, and automatically nested ZIP extraction are not supported. Supported capacity and throughput depend on the device and source; no fixed transfer-speed guarantee is made.

The repository contains current development source and may be ahead of the distributed TestFlight build. App Store/TestFlight releases use a separate signing and review process.

Contributing and security

Issues and pull requests are welcome. See CONTRIBUTING.md. Report sensitive issues through GitHub private vulnerability reporting, not a public issue containing credentials or personal media.

License

MIT, copyright 2026 CHEKUSU. ZIPFoundation retains its own MIT notice in ThirdPartyNotices.txt. Included app artwork is described in ASSETS.md. The license grants no rights to imply endorsement or ownership of the Dropack or CHEKUSU trademarks.