According to an Israeli reporter, LG Electronics is developing a mini-version of the curved G Flex phone. The reporter says he saw a prototype phone during a visit to LG's phone factory in Korea, and when he asked his host, he did not deny this. LG hasn't released a flexible OLED phone (or any OLED phone, for that matter) for over a year (The G Flex was announced in October 2013).
LG's G Flex was the first device to use LG Display's flexible plastic OLED display. The G Flex has a 6" 720p flexible OLED display that is curved from top to bottom (unlike Samsung's Galaxy Round which is curved from left to right). The G Flex used a curved battery produced by LG Chem.
I reviewed the G Flex back in March 2014, when it arrived to Israel. It was a very good phone, and the curved display and the fact that you can actually flex it a little is actually a very cool novelty. My main problem was that it's a very large phone - so I'm happy LG is developing a smaller version.