Mopup › For developers

Clean up after your builds and coding agents

Build tools cache everything. Coding agents start dev servers and leave git worktrees behind. Docker keeps growing. Mopup finds all of it on your Mac, says what each item is, and removes only what your tools can rebuild or what you pick.

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Build caches, each with what removing it means

Xcode's DerivedData, device support files, simulators and SwiftUI previews. Gradle caches, Android Studio caches and emulators. npm and Yarn caches, Puppeteer and Playwright browsers, and Node build caches. Old Flutter SDKs and the Pub cache, Homebrew downloads, JetBrains IDE caches, and the pip, Go and Cargo caches. Anything you might want back, like Xcode archives or an emulator, is marked Your call and left unticked. The Storage section adds up all Xcode keeps, simulator runtimes included, and says where to remove the runtimes you no longer test on.

Mopup's Cleanup section on a demo developer Mac: Xcode build data at 28.4 GB, device support files, old simulators and Android caches, each with its size and what removing it means.

Old projects and merged worktrees

The Projects section looks through the folders you keep code in for generated folders: node_modules, .next, .turbo, Pods, target, .build, .gradle, .venv and more. It ticks them in projects you haven't touched for 30 days, except Python environments, which are your call. bun and pnpm share files between projects, so Mopup counts shared files once and shows what deleting really frees.

It also finds git worktrees you're done with. A worktree counts as finished when its branch is merged, or its pull request merged on GitHub (asked through your gh command, so squash merges count), and it holds nothing but generated files. Removal runs git worktree remove, never --force: anything uncommitted stops it, and the branch and its commits stay.

Mopup's Projects section on a demo Mac: merged git worktrees with their pull request numbers, what removing each one frees next to the bigger size Finder shows, and 13 items selected for 23.5 GB.

The dev servers nobody stopped

Activity Monitor shows a dev server as dozens of separate processes. Mopup shows it as one row: the command, the folder it runs in, the ports it listens on, how long it has run and sat idle, and the app it was started from, such as your terminal or editor. Stop it, and everything it started stops too.

Helpers like workerd and esbuild that kept running after their dev server quit.
Gradle and Kotlin daemons, language servers, emulators and simulators, with one button for the idle build daemons.
A notification when a dev server has sat idle for hours, or let Mopup stop idle servers by itself.

Mopup's Developer Tools on a demo Mac: a bun dev server idle for 2 hours holding 5.08 GB, then Docker Desktop, an idle Gradle daemon, an iOS simulator and a Kotlin daemon, each with a Stop button.

Docker, through Docker

Mopup asks Docker what its build cache, stopped containers, unused images and volumes take, and has Docker do the pruning. Only the build cache is ticked for you. Docker Desktop's memory shows next to your other developer tools, with a Stop button.

Built not to touch your work

Source code, git history and documents are never part of a cleanup.
A worktree with anything uncommitted is never removed.
Caches and build output are deleted for good, since your tools rebuild them. Files and apps you pick yourself go to the Trash.
Scanning and cleaning happen on your Mac. Only update checks, asking GitHub which pull requests merged and, with a yearly plan, fetching your renewed license use the network.

Pricing

Free to scan, and your first 2 GB of cleaning is free. Then $24.99 a year, or one payment of $39 if you buy by November 30 ($59 after). Both cover every Mac you own. Team plans cover 5 or 10 people. See plans.