ButterKit

ButterKit is a native macOS app for creating, localizing, and publishing App Store screenshots. It's built by Zach Spitulski, a solo developer working on it full-time out of Sacramento, self-funded with a lean team and obsessively focused on the indie app developer workflow.

The problem it targets is familiar to anyone who has shipped an iOS app: capturing screenshots from Simulator, building mockups in Figma or a similar tool, exporting at multiple device sizes, redoing the whole thing for each locale, and then dragging files into App Store Connect by hand. Most existing tools are web-based, watermark exports, or gate basic functionality behind a subscription before letting you export anything useful. For many indie developers, the screenshot and localization pass tends to be the last painful step before a release, and the one most likely to get rushed or skipped.

How ButterKit approaches it:

- Runs entirely on the Mac. No servers, no accounts, no cloud storage required. 3D device mockups are rendered with Metal at up to 120fps, so editing feels like a real design tool rather than a slow web form. Everything stays local by default, which also keeps costs low enough to justify a one-time purchase option.

- Captures directly from Xcode Simulator with one click, or links to a Fastlane folder so new builds refresh designs automatically the next time the app is opened. Drag and drop of PNG or JPG also works for screenshots generated elsewhere, including from Xcode UI tests.

- Two translation engines. On-device covers 18 languages, runs offline, and needs no API key. Cloud covers all 50 App Store languages using a bring-your-own API key billed by the provider you choose, with adjustable creativity. Designs stay synced across locales as text changes, so retranslating does not blow away layout work.

- One-click upload of screenshots and app metadata (description, what's new, promotional text) to App Store Connect via the official API, in the correct order for each device size and language.

- Real, editable 3D devices with bundled templates, full font and gradient controls, and the ability to span artboards for panoramic layouts. A community marketplace adds more templates and add-ons over time.

- Built-in MCP server, so agents like Claude Code, Cursor, and Codex can drive the whole pipeline (capture, design, translate, publish) from a prompt. This is one of the newer features and probably the most experimental piece, so feedback there is especially welcome.

Primarily aimed at Apple platforms (iOS, iPadOS, macOS, watchOS, visionOS), with some Android support including a Pixel 10 Pro 3D model and screenshot presets.

Pricing is a one-time purchase or a subscription, with a free watermarked tier and a 14-day no-questions refund. Pro removes the watermark and unlocks metadata syncing across all localizations. There's also a 50% discount for students, educators, veterans, and first responders. Requires macOS 15.6 or newer, works best on Apple Silicon, Intel supported.

Feedback welcome on workflow, the MCP integration, and the pricing model.

https://butterkit.app">https://butterkit.app