From the TAALES website:
Kyle, K. & Crossley, S. A. (2015). Automatically assessing lexical sophistication: Indices, tools, findings, and application. TESOL Quarterly 49(4), pp. 757-786. doi: 10.1002/tesq.194
TAALES is a tool that measures over 400 classic and new indices of lexical sophistication, and includes indices related to a wide range of sub-constructs. TAALES indices have been used to inform models of second language (L2) speaking proficiency, first language (L1) and L2 writing proficiency, spoken and written lexical proficiency, genre differences, and satirical language.
Starting with version 2.2, TAALES provides comprehensive index diagnostics, including text-level coverage output (i.e., the percent of words/bigrams/trigrams in a text covered by the index) AND individual word/bigram/trigram index coverage information.
TAALES takes plain text files as input (it will process all plain text files in a particular folder) and produces a comma separated values (.csv) spreadsheet that is easily read by any spreadsheet software.
You can find all the info here. Windows and Mac versions available for free.