Just received another fantastic Arduino compatible board - FemtoUSB https://femto.io/ available here https://www.tindie.com/products/femtoduino/femtousb-atmel-arm-cortex-m0/ .
Not only is it Arduino compatible, but it is ARM based which opens a lot more possibilities for the future ;-). It is miniature, one of the smallest controller boards that I have seen (competing with bare ESP-12 module), and comes with cool onboard RGB LED .
This board is courtesy of the great Femto.IO people. They have some really cool stuff, and I hope to support it all in the future :-)
Here are some pictures:
Here is the powered up board with the cool LED cycling through RGB colors :-) :
I have placed it next to a Nano to show how small it really is. The Nano looks huge next to it...
Hope to have it supported in Visuino in the next couple of days :-)