UART

FTDI
http://www.ftdichip.com/Android.htm

Prolific
https://play.google.com/store/apps/details?id=tw.com.prolific.app.pl2303terminal&hl=ja
http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=230&pcid=41

silicon labs
http://www.silabs.com/Support%20Documents/TechnicalDocs/an809.pdf