PMR - Progressive Muscle Relax is an iPhone app designed to guide users through progressive muscle relaxation (PMR) sessions independently. The app provides detailed instructions, both verbally and in writing, on how to perform each exercise, indicating when to tense and relax specific muscle groups. Users can customize the duration and number of iterations for each exercise, allowing for flexibility in session length. Additionally, the app offers a variety of voices to guide users, with options to adjust the pace and pitch of the voice or play music during sessions.

Progressive muscle relaxation, developed by Edmund Jacobson, aims to reduce muscle tension through focused attention on alternating between tension and relaxation. This technique is commonly used in behavioral therapy for various conditions such as anxiety disorders, high blood pressure, headaches, and stress. The app provides initial free sessions and later offers a subscription-based model to continue sessions ad-free.