Too Long; Didn't Read
Longan Nano could be the most inexpensive Nano development board currently available. With only $4.9, you will get 128KB Flash, 32KB RAM, 32K RAM, 160x80 LCD, TF card slot and even an acrylic case. The main chip on the board is a GigaDevice GD32V Series microcontroller. The board manager URL for Arduino IDE is: http://://://bigbits-oss-cn-qingdao.aliyuncs.com/Arduino_for_GD32V/package_longduino_index.json.