Rosary Guide is an iPhone application developed by Big River Software LLC. It is a free program that falls under the category of Education & Reference. This simple guide is designed to assist users in praying the five-decade Rosary.

The main features of Rosary Guide include the auto-selection of the Mysteries for the day of the week, the option to adjust the Mysteries for Advent and Lent, and the choice between Luminous or Traditional Mysteries. Additionally, users have the option to include optional Latin prayers and the app saves their place for the day.

It is important to note that when the option to adjust the Mysteries for Advent and Lent is enabled, the order of the daily Mysteries is automatically adjusted according to the practices of EWTN® and the user's diocese. However, it is also stated that this practice may vary depending on the user's locale.

Overall, Rosary Guide provides a straightforward and accessible way for iPhone users to engage in the spiritual practice of praying the Rosary. Its user-friendly interface and customizable features make it a valuable tool for those looking to deepen their prayer life.