NASM Certified Personal Trainer and popular YouTuber Kevin, KevTheTrainer, recently took a deep dive into the Muscle Booster app — a workout app designed to help users build muscle, lose weight, and stay motivated through personalized training plans.

In his detailed video review, Kevin broke down the app’s features, pricing, usability, and overall value.

Here’s what he had to say.

A Tailored Training Experience

Kevin began by highlighting Muscle Booster’s goal-oriented setup. Upon launching the app, users are asked to define their primary fitness goal — muscle gain or weight loss — and provide details like body type, target zones, and fitness level. This information powers a customized training plan that can be performed either at home or in the gym.

He noted that home-based workouts rely solely on bodyweight movements, while gym plans incorporate equipment. However, Kevin pointed out that if you have dumbbells at home, you’ll need to select the “gym” option to take advantage of them — a small quirk in the otherwise seamless setup process.

Structured Plans and Smart Flexibility

Each user’s plan is neatly organized in the app’s “Plan” tab, featuring main workouts, additional workouts, and designated rest days. Kevin praised how easy it is to preview upcoming sessions — including duration, exercises, and required equipment — before starting. He found this preview feature particularly practical, ensuring users aren’t caught off guard mid-workout.

The exercise demonstrations received strong marks. Kevin appreciated the app’s use of animated models highlighting the specific muscles engaged, alongside written guidance and video examples. The ability to swap out exercises based on available equipment also impressed him, offering a layer of flexibility not always found in similar apps.

Comprehensive Workout Collections

Beyond the main plan, the “Workouts” tab includes collections like strength training, morning routines, recovery sessions, and cardio. Kevin noted that while the home workouts are limited to bodyweight exercises, gym-based routines can run nearly an hour and include substantial strength training volume.

He also commended the exercise library, which allows users to explore moves by muscle group — though he found its organization clunky and its functionality confusing, as tapping an exercise automatically starts a workout rather than letting you build custom routines.

Nutrition: Useful, But Not Yet Fully Cooked

Nutrition plays a major role in any transformation, and Kevin spent time evaluating Muscle Booster’s meal planning features. Each day’s plan includes recipes with serving adjustments, macronutrient breakdowns, and swap options for dietary preferences — from vegan to keto to Mediterranean.

However, he felt this section lacked depth and flexibility. Meal plans appeared randomized, calorie targets were unclear, and the absence of video recipe demos limited accessibility for beginners. “It’s functional,” Kevin said, “but could use a lot more context and customization.”

What Works — and What Doesn’t

The Good:

Kevin’s biggest praise went to the workout experience itself. He described the training sessions as comprehensive, balanced, and easy to follow, with proper warm-ups, cooldowns, and logical progressions. The animation guidance and rest structure stood out for clarity and usability.

He also liked how adjustable the app is — from refocusing target zones to switching between home and gym plans, Muscle Booster gives users control without overwhelming them.

The Not-So-Good:

On the downside, Kevin flagged the lack of weight-tracking functionality. Users can’t log the amount of weight they lift over time, limiting the ability to measure progress. He also criticized the exercise library’s rigid design and the meal plan’s limited guidance. Finally, he suggested the app would benefit from offering a free trial, since there’s currently no way to test it without paying.

Final Verdict

Kevin wrapped up his review on a positive note. “If you’re looking for a fitness app to help with strength training and are willing to pay a premium price, Muscle Booster gets the job done,” he concluded. The app’s workout quality, adaptability, and ease of use make it a standout choice — even if the nutrition features and progress tracking leave some room for growth.

In his words, “For what it provides in terms of exercise, it’s definitely a worthwhile option.”