Cannot get ui auto monkey to run

I cannot get the ui auto monkey to run on iOS. I run the script and nothing happens. It opens the app that I have selected on my device and moves it to the background and then does nothing. I used the ui auto monkey.js script on this repo: http://ift.tt/1wqYZDO. The following messsge appears sometimes:

'Target failed to run: permission to debug (app name) was denied. The app must be signed with a development identity (e.g. iOS developer)'

I am running it through instruments for Xcode 7. I am trying to stress test a debug build on an iPhone 6 device. I had assumed that it would be similar to run to the Monkey tool for Android, but I am more familiar with Android than IOS. When I did Android stress testing I did not need to have the project code built in Android Studio but maybe for iOS, I do? As far as error messsges or output the above message is all I get. So I do not have much to go on other than that. I tried different approaches and searched on the internet to see if other people had the same problem but have not been successful. Any suggestions greatly appreciated. Thanks