nRF9160 Thing Plus Hookup Guide
Circuit Dojo, Ell C 
Debug Serial Usage
The nRF9160 Thing Plus comes with an on-board Silicon Labs CP2102 USB-to-UART chip. You can use it with most serial terminal viewers. If you have an older version of Windows you will have to install the driver. The download is located here.
Here are some recommendations for software to communicate with the nRF9160 Thing Plus. No matter what program you use, the standard baud rate for the console is 115200. All other options are standard/default (8 bits, oon-parity, 1 stop bit).
Multi-Platform
nRF Connect For Desktop - LTE Link Monitor
If you haven't already, make sure you check out the LTE Link Monitor. It's a great multi-purpose tool for using and debugging the nRF9160 Thing Plus.
CoolTerm
CoolTerm has been my go-to for testing and debugging. Fortunately it's also multi-platform! The download is located here.
Mac OSX & Linux
screen
You can use screen to view your debug output. Here's a typical command:
language:bash
screen /dev/tty.SLAB_USBtoUART 115200
The major drawback of using screen is that it does not save your history. It's better to use other utilities for that purpose.
Note: depending on your system your serial port may be named something different from /dev/tty.SLAB_USBtoUART. You can check your dev folder like this to check which one may be it:
language:bash
ls -l /dev | grep SLAB
cu
You can also use cu to display your debug output. Here's an example:
language:bash
sudo cu -l /dev/tty.SLAB_USBtoUART -s 115200
If you notice, it requires super user permissions. (This is the only drawback to it IMHO)
To escape from your session type ~.