PrepExams.in released JEE Main Mock Tests with 2000+ questions fully solved. The mock tests are downloadable, and the trial version is free with full features, but limited to 30 questions.
The exam engine uses state of the art technology required for such mock tests. The features include online activation, fully solved papers, learn mode/exam mode, retake in weak areas, category wise scoring.
Download page: JEE Main Mock Tests (http://www.prepexams.in/JEE-Main/jee-main-product-details.html)
Website: prepexams.in mock tests (http://www.prepexams.in/)