Newt Manager (newtmgr) is the application tool that enables a user to communicate with and manage remote devices running the Mynewt OS. It uses a connection profile to establish a connection with a device and sends command requests to the device. The newtmgr tool documentation can be found under /docs which are published at http://mynewt.apache.org/latest/os/modules/devmgmt/newtmgr.html
Build the newtmgr tool as follows:
cd newtmgrgo build