What is the best learning app to learn Japanese?

My legs were jelly when i try to run through the snow

Bill excelled in two kinds of performance art, ballroom dancing and the tango. what kind of phrase are the bolded words?

Ijust done my mock exams recently and i am in year 11, i did not do very well and i am stressed out about it, i spent time revising but it didn't work out for me, can someone tell me any good tips on how to revise effectively so for my next mocks i am well prepared.