wtf is simslim?

simslim is a command-line tool for Mac users who work with iOS simulators, the virtual iPhone screens developers use to test apps without a real device. Normally, each simulator you boot starts up around 180 background services it does not actually need for testing, things like Siri, search indexing, photo analysis, and cloud syncing. Those services eat memory, which means a laptop can usually only run a handful of simulators before it slows to a crawl. simslim turns those unnecessary background services off for a given simulator, which the README reports cuts that simulator's memory use by roughly four times. In their example, a machine with 16 gigabytes of memory went from struggling with about five simulators to comfortably running nineteen at once. You control this through simple commands: one to slim a simulator down, one to put it back to normal, one to check how slim it currently is, and one to measure its memory use directly. The tool also includes a separate, opt-in disk cleanup feature that can remove temporary files, caches, and logs from a simulator to free up storage space, with a preview mode that shows what would be deleted before anything actually is. There is also an optional Mac app, built with SwiftUI, that wraps the same functionality in a visual interface with searchable lists and one-click controls. Turning off these background services does have tradeoffs: features like search, push notifications, and app store testing tools stop working on a slimmed simulator unless you specifically choose to keep them running. simslim is aimed at iOS developers, and especially teams running many simulators at once for automated testing or continuous integration, where fitting more simulators on one machine directly speeds up how much testing can happen in parallel. It requires a Mac with Xcode and an iOS Simulator installed, and is released under the MIT license.