Oppo A31 2015 official Pictures. Oppo A31 2015 is a Smartphone of oppo. The Oppo A31 2015) Android Smartphone. Announced Apr 2015. Features 4.5″ Display, Snapdragon 410 Chipset, 8 MP Primary Camera, 5 MP Front Camera, 2000 MAh Battery, 8 GB Storage, 1000 MB RAM. Oppo A31 2015 price starts.