A tool created by the developers at LinkedIn that lets you run iOS tests in parallel using multiple simulators. In its simplest form, Bluepilll will run your tests on 4 simulators in parallel, producing a JUnit report when the test run completes. It will automatically pack tests into groups with similar running time, and can run in headless mode to reduce memory consumption. You can also supply a config JSON file to customise how your tests are run, including options to specify how many simulators to run, which device to use, how to handle failures, output formatting, and more.