A tool to help find out which characters or chargrams are most frequent in a text or a set of texts.
The purpose could be to check out which characters or character sequences are most frequent (e.g. in normal English text the letter E followed by T will be most frequent, THE and ARE will be high frequency 3-chargrams), or it could be to check whether your text collection contains any oddities, such as accented characters or curly apostrophes you weren't expecting.
See also: Character Profiling