Flex Fitness Workout Tracker 4+

Exercise, Planner, Gym, Weight

Flex Artificial Intelligence Inc.

    • 4.6 • 1.6K Ratings
    • Free
    • Offers In-App Purchases


The best free and fun workout app to build muscle or lose weight fast.
Turn the gym into a game with Flex. Compete with friends, compare your progress with world rankings, and connect with others in the community.
Yes, really free with no ads and no catches. Premium offers a better experience with features like auto progression and logging on Apple Watch.
Follow us and our craziness:
- Instagram @flex.ai
- Tiktok @flex.app
- flexfitnessapp.com

• Basic premade workout programs
• Build or customize your own program and freestyle workouts
• Workout guide and logger
• Share your workouts and routines with friends
• View your progress and stay consistent: workout calendar, exercise stats, streak, bodyweight tracker, calories tracker, steps tracker, workout notifications

Flex Premium:
• Logging on the Apple Watch app
• Auto Progression: Automatically increases or decreases the difficulty of your logged exercises next session.
• Unlock Premium programs
• Unlock Premium freestyle workouts
• Premium workout experience: music integration, plate calculator, etc.

Flex is the free, simple, and engaging app that does the planning and tracking so that you can just focus on your workouts and achieve your goals. Flex can automatically increase or decrease the difficulty of your exercises in your program based on past performance.

Hundreds of workouts and programs for you. Find and use the most effective workouts and programs designed by personal trainers, tailored to your goal and whether you workout at the gym or at home.

Forget about researching exercises, programs and keeping track of all your progress. Flex handles that and makes working out more engaging with features like streaks and progress charts.

Freestyle workouts:
Whatever your time commitment, physical goals, experience, or access to equipment, Flex has the right workouts for you. Choose any combination of equipment, goals, muscles worked or quick freestyle workouts.

Already have a fitness program you use or want to customize your own?
Edit one of our programs or build your own into Flex with the custom plan builder.

Real-Time Workout Guide:
Flex’s workout guide will lead you through your workout step by step, telling you which exercises to do, how to do them, how long to rest for optimal results and notifying you when you need to start your next set. You also have the spreadsheet view where you can fully modify your workout on the fly. Move around exercises, change exercises, add/remove sets. Control your music without leaving the app thanks to native Spotify and Apple Music integrations.

You can't improve what you don't measure. With Flex, you can track:

How consistently you’re exercising with the calendar feature
Your total calories burned daily, calculated from workouts/steps/BMR
Your bodyweight over time
Your steps with a 10k daily goal via the Apple Health integration
Your exercise progress with the exercise stats
Your workout history

An even easier way to workout with Flex Apple Watch:
Use the Flex apple watch app to log sets and complete workouts without needing to constantly check your phone. Sync your data and close your activity rings.

What’s New

Version 2.16

- Introducing Flex widgets for your Home Screen & Lock Screen: view your scheduled workouts and current streak progress at a glance without opening the app. To add a widget to your Home Screen, tap and hold in the Home Screen, tap the "+" button on the top left corner. You can also add widgets from Flex onto your Lock Screen by long-pressing the Lock Screen.
- Get notified when you become the most active person of the day among people you follow
- Get notified when you're about to lose your workout streak
- Workout guide UI optimizations
- Bug fixes

Ratings and Reviews

4.6 out of 5
1.6K Ratings

1.6K Ratings

~(0_0~) ZombieGhost ,

Great App

I’ve very often struggled to maintain a consistent workout routine without relying on a trainer. I started using this app to supplement my regular training routine. I’ve used it on days where I just wasn’t sure what to focus on, and it has helped by making it easy to target a specific muscle group or filter by equipment. The smart progression and auto tracking has really helped me see tangible progress in my training. It’s taken a lot of the effort out of planning my workouts, making actually going to the gym much easier and enjoyable.

I do like how it is easy to swap out an exercise, or adjust the number of reps or weights on the fly. This has been useful when the gym is busy and I may not have access to the right equipment, it makes it really easy to adapt a workout. The animations and descriptions of what to do in an exercise are also really helpful.

I would recommend this to anyone who struggles to track and maintain a consistent workout plan.

Developer Response ,

Thank you so much for your review! Please let us know if there's any way we can further improve the app for you by sending us a report/message in app.

Karmma333 ,

Great Work Out app for Gym and At Home!

I have been through my fair share of work out apps, everyone of which limits what I can do and what types of work outs I can create for ME, so I wasn’t expecting much from Flex when I saw it advertised thinking it was like others but decided to try it out. I was pleasantly surprised when I saw I can create my own work out’s however many that it, my own work out plan. They let you completely customize and decide what you are going to be doing with your own work outs for free. They do provide work outs themselves and plans but you have to pay for some of them which is only expected. For someone who has a work out plan in their mind and just need the structure for said plan this app is perfect.


Best Workout App for Intermediate and Advanced Training

I’ve been weight training for about 12 years and one of the biggest keys to success in the gym is consistency workout to workout. Flex is built exactly for this.

It allows you to build your own workouts in a simple, easy to use format.

There are premade workouts available for beginners but I don't think this is really the app’s strength.

It remembers your last weight and set for each exercise and carries it over to the next workout.

It tracks your rest (which you can customize)

And if you make modifications intra-workout, you can save those for the next time as well.

The stats dashboard is helpful for tracking progress, though could use some improvement and more detail.

Try it out for free, but if you have an apple watch, you’ll definitely want to pay for it, the logging on the watch has changed my ability to stay focused and keep my phone away while working out.

Overall an amazing app if you want a highly customizable, simple interface logging app that doesn't push a specific training style or set of workouts.

Developer Response ,

Wow, thanks for taking the time sharing your detailed review with everyone! 12 years gymming is very impressive, that’s the sort of lifestyle we try to help promote 💪🏻

App Privacy

The developer, Flex Artificial Intelligence Inc., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Linked to You

The following data may be collected and linked to your identity:

  • Health & Fitness
  • Contact Info
  • Identifiers
  • Usage Data
  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Some in‑app purchases, including subscriptions, may be shareable with your family group when Family Sharing is enabled.

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