Start64!Chinese OEM recently launched two high-end smartphones, the R7 and R7 Plus, which are already available for pre-order in some countries. They are expected to hit shelves next month, but there's no confirmation on that for now.

But that won't be the only Android smartphones to be launched by Oppo this summer. It looks like an unannounced Oppo A51 has just popped up at TENAA, the Chinese regulatory comission.

Judging from the specs listed the Oppo A51 is a mid-range smartphone that will ship with Android 5.0.2 Lollipop operating system out of the box. That will greatly help Oppo's mid-end smartphone to stand out from other devices in the same price range.