Scholastic Reading Counts!
Scholastic Reading Counts! is a reading program from Scholastic that uses the Lexile Framework to measure student success and meet AYP goals. Subscription-based, it features a wealth of reading resources and quizzes for the gamut of students.
This link goes to the research page on the Scholastic site for their flagship reading product that uses Lexile. PDF papers include: "Raising Students Who Want to Read," "Matching Books to Readers," "Reading: Voluminously and Voluntarily," "Matching Students to Text: The Targeted Reader."