I'm looking for someone else to verify this: 1. Open up your iOS project in XCode. 2. Open Activity Monitor, click the Memory tab. 3. Find XCode and note the number in the "ports" column. This may only be available in Mavericks. 4. Run your app in any of the simulators, then quit it. 5. Check the number of ports again in step 3. 6. Repeat a few more times, just to make sure. For me, the number increases significantly every time I run my app. After several hours of work it has climbed from 300 to 3000.