Caps Lock
Pinyin input is the most common way to type Chinese: you type the pronunciation in Latin letters, without tones, and pick the characters. Klava shows each common word in pinyin with the characters above it, so you practise both the spelling and the vocabulary.
Pinyin uses ü for some syllables, usually typed as v on a standard keyboard. Practise whole words rather than single syllables: input methods work faster with full words.