New decks are added using a rich content editor and the vocabulary can be studied using 40,000 example sentences.
All decks (even those not created by you) can be annotated with notes. These notes are aligned with the context in the deck such they'll always match up line-by-line, regardless of window size or formatting. Furthermore, any chinese written in the notes will trigger the built-in dictionary, just like in the decks.
Practice your comprehension by listening to each practice sentence and then write down the characters (or pinyin).
Memorize words quickly by seeing them in a familiar context (ie. in sentence that only use words you already know) and write their pronounciation (in pinyin) to continue.
Push your limits by practicing new words or words you're just about to forget. New words are introduced until you reach a 20% recall failure rate.
Overlearn by studying words that you haven't seen in a long time, regardless of whether the learning algorithm believes you've about to forget them. This mode is relaxing, builds mastery, and improves your comprehension by showing you known words in completely new sentences.
In speed mode, you are only quizzed in the words you're actively learning right now. This makes it very quick to review large quantities of vocabulary but with less attention paid to the broader context.
In mastery mode, you are quizzed in the entire sentence, forcing you to read it and notice the context of the words you're learning. An added benefit to this mode is that forgotten words are quickly discovered even if they're not part of your active set.