Manages iOS Simulator devices and app tests with xcrun simctl: lifecycle, install/launch, push and location simulation, privacy permissions, deep links, status-bar overrides, screenshots/video, log streaming, app containers, and targetEnvironment(simulator).
SkillScore91Maintained
Automatic
◆Coding pack
Last verified 8/14/2026
What it changes
Passed 20 of 22 test cases with the skill, and 18 of 22 without it.
Without skill82%
With skill91%
Checks it passed that the model alone missed
Advises against passing GPX file paths to simctl location run.
Recommends querying simulator UDIDs dynamically from simctl JSON list output.
Recommends using simctl location booted start for passing custom coordinate waypoints.
and 1 more in the full report
3 fixed17 passed either way1 still failing1 broke
Pass-rate lift
+9 pp
Tokens
+180%
Agent turns
0%
Response time
-34%
Model gemini-3.6-flashMeasured 8/14/2026v120 of 22 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 3 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 3
Prompt
I need to record a video of my app running in the simulator using `simctl io booted recordVideo`. I want to make sure the recording uses transparent rounded corners by passing `--mask alpha`. I also want to terminate the recording script using `kill -9` (SIGKILL). Will this setup produce the expected video?
What was checked, without and with the skill
Checked
Without skill
With skill
States that the alpha mask option is unsupported for video recording and falls back to black.
Missed
Passed
Explains that terminating video recording with SIGKILL corrupts or loses the output file.
Passed
Passed
case-11 · gemini-3.6-flash · 8/14/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md433 lines2 files
iOS Simulator
Load the simctl command reference when you need
complete command tables, JSON parsing, privacy/status-bar values, Logger filter
setup, or boot recovery commands.
# List all available simulators grouped by runtime
xcrun simctl list devices available
# List installed runtimes
xcrun simctl list runtimes
# List only booted devices
xcrun simctl list devices booted
# JSON output for scripting
xcrun simctl list -j devices available
Parse JSON output to find a specific device programmatically. See references/simctl-commands.md for jq parsing examples.