This simple, yet compact, breakout board does 4 basic things:

1. Provides the missing hardware necessary to enable the module's DC/DC voltage regulation, thereby extending battery life,
2. Provides an ARM 10-pin connector for programming/debugging of the module,
3. Provides a typical 6-pin connector for serial input and output to and from the module,
4. Provides a 2.54mm pitch pinout for the remaining useful pins on the module.

For background information, see: https://www.openhardware.io/view/376/MySensors-NRF5-Platform