The Synwit SWM product family is a Chinese market offering and appears to consist of the SWM050, SWM100, SWM120, SWM150, SWM180, SWM181, SWM220, SWM240, and SWM320.
The company has "a core technical team from Silicon Valley". The chips have fewer peripherals and less RAM than their similarly priced Western competitors.
However, I read about the SWM050 in a blog post and was intrigued to see what a Chinese market Cortex-M0 would be like.