Question: How do you debug react-native when it is running on device ?

Answer: 
There are little hack in here for IOS.
In XCode open AppDelegate.m from project folder, comment the line with jsCodeLocation declaration and add near it something like this:

```
jsCodeLocation = [NSURL URLWithString:@"http://%YOUR_PC_IP%:8081/index.ios.bundle?platform=ios&dev=true"];

```

, where %YOUR\_PC\_IP% is IP of your dev machine on local net.

Then open project named RCTWebSocket wich located in Libraries folder and then open from this project file RCTWebSocketProjectExecutor.m. Next, comment the line with host declaration, then add near it something like that:

```
host = @"%YOUR_PC_IP%";

```

Almost done. Run app on your device with XCode and make sure that your IPhone can see your develop machin via internet.

After it launches make sure that node server is running (command "react-native -- --start" in root project folder) and open via chrome this page: <http://localhost:8081/debugger-ui> . Plus, option Debug JS Remotely must be enabled in your app on your IPhone. (Shake action, then tap in opened menu Debug JS Remotely, that is it.)

Now open dev console and have happy debugging.
***2*** options exist:

**Remote debug:** this would go over network, so it can be laggy.
-----------------------------------------------------------------

1. Run app on device (install it whilst its plugged in)
2. Shake device (Android devices need to be **vigorously shaken**)
3. Press `settings` on the dev menu, and under `Debugging`, press `Debug server host and port for device`
4. Enter your debug server's IP address and port (usually 8081 unless you changed your settings of the debug server), e.g. 255.255.255.255:8081. Your ip address is the local IP address that your computer has. Ensure the device is on the same network. For mac users, open `System Preferences` → `Network` → `Wifi` → Under `Status: connected`, there is an IP address, use that.
5. You can unplug the device
6. Ensure debug mode is on (Shake device vigorously again, press Debug)

Wired debug: relatively better for slow connections
---------------------------------------------------

1. Install app on phone
2. If android, set up port forwarding with `adb reverse tcp:8081 tcp:8081` and if iOS, follow the steps from [RN docs](https://facebook.github.io/react-native/docs/debugging.html#debugging-on-a-device-with-chrome-developer-tools))
3. Enable debug on device