Comparison

Katalyst vs Fiix Body

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Katalyst

This app enhances a revolutionary workout system using Electro Muscle Stimulation (EMS) to engage all muscles simultaneously. It offers a full-body workout in just 20 minutes, with zero joint load. Access diverse workout programs and control intensity for personalized training.

Highlights
  • Electro Muscle Stimulation (EMS) training
  • Full-body engagement
  • 20-minute workouts
  • Zero joint load
  • Diverse workout library (strength, power, cardio, recovery)
  • Adjustable impulse intensity
  • Offline workout access
Features
Read full description

The Katalyst App is the companion to the Katalyst Suit, a wearable training system powered by advanced fitness technology. Together, they deliver a full-body workout no app can deliver on its own. A Katalyst Suit is required to train. The Katalyst Suit is an FDA-cleared, patented system that uses Electro Muscle Stimulation (EMS) to engage your major muscle groups at once. Low-frequency impulses mimic the signals your brain sends to contract a muscle. Pair them with simple bodyweight movements and every rep works harder, engaging up to 90% of your muscle fibers, including the deep back stabilizers most workouts miss, with zero load on your joints. ALREADY HAVE A KATALYST SUIT The app is free. Log in or create your profile for unlimited access. NEW TO KATALYST Explore the app and preview the workouts. Get your system at katalyst.com. WORKOUT MODES FOR EVERY LEVEL Programs built by professional trainers, from your first session to elite. - Strength: complete full-body strength in less time - Power: explosive sessions that recruit fast-twitch fibers - Cardio: lower-frequency sessions designed to build endurance, with quick recovery for daily use - Recovery: active and passive modes with massaging impulses to finish like the pros
- Freestyle mode: Choose a mode, set your intensity, and train your own way. TRAIN LED OR TRAIN SOLO In guided classes, your trainer adjusts intensity in real time so you can focus on the movement. Prefer your own pace? Run independent programs on your terms. ALWAYS IN CONTROL Dial intensity up or down, or target a specific muscle group, at any moment. How hard you train is always your call. TRAIN ANYWHERE Stream any workout on demand, or download sessions ahead of time for when you'll be offline. BUILT FOR YOUR SETUP - Apple Watch: adjust overall intensity, pause, and resume workouts right from your wrist
- AirPlay: put your instructor on the big screen and use your iPhone or iPad as the remote Get more strength and more out of life with Katalyst Suit workouts. 
katalyst.com

About

Fiix Body

This digital physical therapist guides you through elbow pain recovery at home. It provides personalized therapy schedules, tracks your progress with data and surveys, and offers helpful tips and videos to maximize your treatment experience.

Highlights
  • Personalized therapy schedules
  • Progress tracking and weekly scores
  • Pain assessment surveys
  • Comparison graphs with other users
  • Helpful tips and video guides
  • Push notification reminders
Features
Read full description

Your own digital physical therapist that keeps you on track! Fiixing your elbow pain at home with the Fiix Elbow device just got even easier with the Fiix App. The app tells you what to do, when to do it and tracks your success! CHOOSE YOUR THERAPY SCHEDULE Pick the days and times for your Fiix Elbow device sessions and exercise sessions, based on YOUR schedule and at YOUR convenience. Stay on track with push notifications to your smart phone or smart watch when it’s time for treatment. TRACK YOUR PROGRESS If you like data, you’ll love how the app tracks your progress so you can see how you’re doing every step of the way. You get scores each week measuring your adherence to the therapy program so you can celebrate your success. Plus, assess your pain with the weekly survey, and check out the graph that shows how you compare to others throughout the 10-week program. MAXIMIZE YOUR EXPERIENCE Take advantage of helpful tips and short videos at your fingertips to get the most out of your treatment. The Fiix App is here to support you every step of the way so you can get back to doing the activities you love without the elbow pain!

Screenshots

Katalyst4 screens
Fiix Body4 screens

Verdict

The call

The clearest difference is monetization model: Fiix Body at free against Katalyst's free with in-app purchases. Fiix Body also leads on ratings volume (298 vs 59). Katalyst's advantage is review sentiment (81% vs 67%). On price, rating, update cadence and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Fiix Body holds the better App Store score, 4.7 against 4.6. That said, the two scores are not equally well evidenced: Fiix Body has 298 ratings behind it against 59, so its average is the more settled of the two. Written reviews complicate that: 81% of Katalyst's written reviews are positive against 67% of Fiix Body's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Katalyst ships an update every 3 weeks, Fiix Body every 5 weeks. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

Scorecard3 real differences · 7 level
Katalyst versus Fiix Body: the parameters behind the verdict, then further details
ParameterKatalystFiix Body
PriceFreeFree
Rating4.6 (59 ratings)4.7 (298 ratings) — better
Positive reviews80.6% of reviews — better66.7% of reviews
Number of ratings59298 — better
Update frequencyEvery 3 weeks — betterEvery 5 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, Apple WatchiPhone, iPad, iPod
Requires iOS16.015.6 — better
Further details — not scored
Size155 MB33 MB
Age rating4+4+
DeveloperKatalyst Interactive Inc.Fiix Body

Customer experience

Katalyst

All ratings59 ratings
Positive88.1%
Neutral3.4%
Negative8.5%
Written reviews31 reviews
Positive80.6%
Neutral6.5%
Negative12.9%

Fiix Body

All ratings297 ratings
Positive94.6%
Neutral3.7%
Negative1.7%
Written reviews6 reviews
Positive66.7%
Neutral16.7%
Negative16.7%

In-app purchases

None

Katalyst

No in-app purchases

None

Fiix Body

No in-app purchases

Questions

Is Katalyst free?
Katalyst is free to download, with no in-app purchases.
Is Fiix Body free?
Fiix Body is free to download, with no in-app purchases.
Which has better reviews, Katalyst or Fiix Body?
Fiix Body is rated higher. Katalyst averages 4.6 out of 5 from 59 ratings, while Fiix Body averages 4.7 from 298 ratings.
Do Katalyst or Fiix Body have ads?
Neither Katalyst nor Fiix Body shows ads.
Which is updated more often, Katalyst or Fiix Body?
Katalyst ships an update every 3 weeks, and Fiix Body every 5 weeks. Most recently, Katalyst was updated on October 25, 2026 and Fiix Body on October 24, 2026.

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