These days it's no longer surprising to hear some new smartphone being flashed with some version of CyanogenMod. But for reasons both subtle and not, running the modified CyanogenMod 11S designed for the OnePlus One on the OPPO Find 7a is still an interesting mix.
This could mostly be attributed to the two devices' common history and their own similarities. OnePlus was a company started by a former OPPO executive. Both companies had partnerships with Cyanogen, Inc. to provided a user experience based on CyanogenMod. And both the OnePlus One and the Find 7a share very similar hardware. It is somewhat a shame that they don't share the software too. But now they can, unofficially.
Unlike the OPPO N1, the Find 7a runs OPPO's ColorOS custom Android user experience. However, with a bit of shoehorning some diligent individuals were able to find a way to install OnePlus One on the Find 7a. It isn't perfect yet, though, and some things are still not working. Calls, WiFi, data, Bluetooth, and the front camera are all working but the rear camera, NFC, and voice wake don't. The system also strangely reports only 3 GB of storage space available.
If you do happen to have an OPPO Find 7a and want to somewhat get the OnePlus One experience, do note that it does require flashing and installing a custom recovery, not exactly for the faint of heart. If you do, however, already have CyanogenMod 11 in your sights, you might want to wait a bit longer as some of the new features, particularly the new theme engine, will be arriving on CyangenMod 11 for everyone anyway.