This book, authored by the Holy Rabbi Dov Ber of Lubavitch, is known as THE KEY to Chassidus (See HaYom Yom – Shushan Purim, Adar Sheni). It explains the entire methodology and system of Kabbalah and Chassidus, and is therefore foundational to unlocking the secrets of Kabbalah and the treasure houses of Chassidus. It is a must read for any serious minded seeker of G-d’s Truth. This app contains access to classes by Rabbi Yossi Markel and Rabbi Benyomin Walters.