I am developing a desktop app to help in working with AT commands called ATCommander, check: http://atcommander.io/
The tool works by sending AT commands via a serial port from your computer to a modem.
Right know it supports the AT command set for u-blox GSM/GPRS modules, so no SARA-N2 module yet.
To use it with SODAQ NB-IoT board for example, you would need to connect it to your computer via USB.
Does SODAQ NB-IoT board has a serial <-> USB interface?
Also I would like to know if such a tool would be useful for SODAQ developers so I could advance it to support SARA-N2?
Your tool looks promising
I think a lot of people would like to have one tool to send at commands to all the available radio modules.
The NB-IoT shield has a Serial interface.
You need a microcontroller board or an serial to usb converter.
We made a sketch for an Arduino Leonardo, M0 and Sodaq Explorer. http://support.sodaq.com/sodaq-one/at/
On this page you will also find the required AT commands and the differences between the commands in the old and new firmware.