The (Tiny) NB1-Node is a very neat development platform to experiment NB1. It is based on the Quectel BC66 module, it has an STM32L071 processor ( you could mount on the same footprint also an L4), USB connection that mimics exactly the Quectel BC66 EVK ( same chip same drivers ) so you can use all of Quectel tools, an on board 2Mbit Flash ( should we try some FOTA over NB1?? ), and last but not least a LiPO connector and charging circuit for testing on the field.
Here picture of top and bottom.
As you can see from the bottom silkscreen we also have part of the STM32L0 ports exposed on the external headers, so that you can very quickly develop your own sensors.