OLL 11
The algorithm, how to recognise it and how to practise it without cheating.
Recommended algorithm
r U R' U R' F R F' R U2 r'11 moves
How to recognise it
A small lightning bolt: the back and left edges with the back-right corner. The front-right corner's yellow faces you.
Its inverse is another case
Do the 11 algorithm backwards, r U2 R' F R' F' R U' R U' r', and you are solving 6.
That's why CubeDojo never scrambles 11 that way: it builds a random state with the case fixed, so you practise 11 and not 6.
Practise 11 now
Random-state scrambles, a timer and spaced review. Free, on the web and on your phone.