Env.plist

Const.swift

import Foundation

class Const {
    
    class var FeedbackSlackURL: String {
        let url = env["FeedbackSlackURL"] as! String
        return url
    }
    
    private class var env: NSDictionary {
        return NSDictionary(contentsOfFile: NSBundle.mainBundle().pathForResource("Env", ofType: "plist")!)!
    }
    
}

Env.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>FeedbackSlackURL</key>
	<string>https://hooks.slack.com/services/.....</string>
</dict>
</plist>