Take a look at Seeeduino XIAO. What a small size and cute looking! It is the smallest member of the Seeeduino family. Seeeduino XIAO still carries the powerful CPU-ARM Cortex-M0+(SAMD21G18) which is a low-power Arduino microcontroller. On the other hand, this little board has good performance in processing but needs less power. As a matter of fact, it is designed in a tiny size and can be used for Arduino wearable devices and small projects.