Based on the user reviews, here are three cons and pros of the Flex Castle app: **Pros:** 1. "Easily customize and manage my fitness journey, love the variety of exercises and tracking features." 2. "Innovative and effective workouts, the app's assessment tool really helps me improve my form and strength." 3. "User-friendly interface and consistent updates, great value for the price and support from developers." **Cons:** 1. "Some features, like personalized coaching, available only with a subscription, feels like a nickel-and-dime scam." 2. "Occasional glitches and crashes, frustrating when working out and disrupting my workflow." 3. "Limited selection of music tracks, could use more varieties to keep workouts engaging and fun." Please note that these sentences are a summary based on multiple user reviews and are intended to provide a general idea of the app's strengths and weaknesses.