What is this overlay?

[Marius]

Good day. 

I expect that my cat might have walked over my keyboard, because when I fly, I suddenly see this overlay, and I cannot identify what it is to turn it off. I have pretty much pressed every key on my keyboard in the hope that it would toggle off, but it just stays there. Does anyone know what this is? (To ED: perhaps a small title text for this kind of thing would be helpful, to say what it is). Does anyone know how I can turn this off?

null

Thanks,
Marius.

 

[SkateZilla]

SARPP

Settings, Special Options, L-39
SARPP Mode