I'm using XCode 7.0b5 and created an Swift app. It runs fine on simulator but crashes on iPhone 4s when running independently (without cable). How can identify where it crashes? I read about possible memory issues. I'm reading in a large textfile, so it needs nearly 200 MB of ram. How can I check it?Answer1:
I think this is a memory problem with the iPhone 4S (200 mb for 4S is a lot). You should read the crash logs in Xcode.
In Xcode with the iPhone connected you can go to Window->Devices, select your phone and press 'View Device Logs'. You will see a list with all the last crashes of the apps and with the information of the crash.
I got the solution. It is the run time. I reduced the file sizes to 10% of the original and everything runs fine. So I can test it and "improve" it to the speed limit of the iPhone 4S. :-)