After flashing a custom ROM, there is a watermark in the top-right of the screen saying
xe6x9cxaaxe5x86x99xe5x85xa5google keyxe5x92x8ctee key
I've googled it and have tried several of the solutions suggested, but none have worked. Interestingly, most people get a slightly different variation of this message, in red.
I've removed "FactoryTest" from my phone, but do not have
com.mediatek.factorymode as some have suggested. I've messed around with my IMEI keys, this did not help. The message also still appears even with the SIM card removed.
Where on the phone could this be stored? My phone is rooted, so if I could locate the file responsible, I could easily delete it.