The Stackz flashcard visualization concept helps to keep the overview over a large amount of words to be learned by representing your current proficiency state with one intuitive view using piles of colored flashcards. The cards are distributed according to the 'mastery level' and colored according to the 'date of the last mastery' - they become darker over time. This system allows distinguishing easy cards from difficult ones immediately, and simultaneously seeing which cards must be refreshed because they have not been reviewed for a long time.

Integrated dictionaries for Japanese and Chinese simplify the process of generating new wordlists from scratch, or automatically from web pages. The dictionaries are also directly available for looking up information during the process of learning words of any of these languages.

Stackz supports any other Unicode language of the Widows operating system as well. The constantly growing online wordlist archive currently contains over 200 wordlists for Japanese, Chinese, Korean or Thai.

A Pocket PC version of Stackz is also available, bringing the Stackz flashcard system to virtually any place. The wordlist files can be directly downloaded to the Pocket PC, which guarantees seamless synchronization of the learning status between the platforms.