Comparison

iFour Core vs Onyx Physical Therapy

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

Head to head
About

iFour Core

This app offers a personalized core workout program designed by physical therapists. It adapts to your individual anatomy and fitness level, providing daily workouts under 10 minutes with video demonstrations. Access nutrition guides and trainer support as a member.

Highlights
  • Personalized core workout program
  • Physical therapy approved exercises
  • Daily workouts under 10 minutes
  • Video demonstrations of exercises
  • Nutrition guides and support
  • Fitness test for customized plans
Features
Read full description

Every individual’s anatomy is different which is why we have designed a customizable, physical therapy approved core program. The iFour Core app addresses specific areas of your core to help you develop the strongest core imaginable without injury. Each workout is under 10 minutes, is suitable for all fitness levels, and can take place in the home or at the gym. As a member of the iFour Core app, you will receive new workouts every day, nutrition guides, and support. FREE 7-day trial for new members! HOW IT WORKS: After completing the iFour Core fitness test, you will get a core strength rating. This rating is broken up based on muscle fibers worked (intrinsic, rectus, obliques & transverse). The iFour Core app customizes the exercises each day based on your fitness test performance and current level of core strength. WHAT MAKES US DIFFERENT: Life is full of surprises, plateaus, and challenges. We created this app with this in mind allowing you to recalibrate your individualized workout formula at any point you feel necessary. Unlike other programs, this is not simply just hitting “reset,” and repeating the same exercises from previous days. This is a full recalculated algorithm taking you from your new “starting point” with a proven plan of attack to help you once again improve. iFour Core Features: Workout & Fitness Planning • Functional yet challenging core rotations, ranging from 5-10 Minutes! • Includes regressions to decrease difficulty and progressions to advance the exercises as you improve. • 323 unique core exercises. • 137 additional core exercises with 6 different pieces of equipment to choose from. • Video demonstrations of all 323 core exercises. • Designed for all levels, whether you are coming out of physical therapy or an elite athlete! • Take the fitness test and as you get stronger, unlock more core exercises prescribed for you. Tracking & Fitness Motivation • Workout along with J, a seasoned trainer for celebrities, professional athletes, and others. • Track your daily progress in both your Fitness Test and Workout History. • Share your results on your favorite social media platform. • Keep up to date and learn with the latest iFour videos. Subscription Pricing & Terms iFourCore is free to download. Ongoing use requires an active subscription, available on a monthly or annual basis. New customers are eligible for a 7-day free trial. Annual subscriptions are billed the total fee from the purchase date. Monthly subscriptions are billed per month. Payment will be charged to your credit card through your iTunes account at confirmation of purchase. Subscription renews automatically unless cancelled at least 24 hours prior to the end of the subscription period. There is no increase in price when renewing. Subscriptions can be managed and auto-renewal turned off in Account Settings in iTunes after purchase. Once purchased, refunds will not be provided for any unused portion of the term. Read our full Terms and Conditions & Privacy Policy: https://www.ifourlife.com/

About

Onyx Physical Therapy

Features
Read full description

Welcome to the Onyx Physical Therapy App! Log on to access your personalized Home Exercise Program on your mobile device. Using this app, you can access your personalized Home Exercise Program with HD Instructional videos. On the 'Messages' tab, you can securely communicate with your Onyx Physical Therapy provider. As you complete your exercises, we'll give you trophies and medals to celebrate your progress! On the 'Awards' tab, you can track these items. Prefer a language other than English? Go to the 'More' tab and select 'Languages' to pick another language option. If you need to book an appointment, please go to the 'Appointments' tab for more info. Make sure to select 'Mark as Complete' when doing your exercises to ensure that your provider can keep track of your progress! You must be an Onyx Physical Therapy patient to gain access. This app integrates with your iPhone's Health app to read daily step count data allowing your provider to monitor your activity.

Screenshots

iFour Core4 screens
Onyx Physical Therapy4 screens

Verdict

The call

The clearest difference is in-app purchases: Onyx Physical Therapy at none against iFour Core's 2. iFour Core's advantage is update cadence (every 2 months vs every 9 months) and iOS requirement (11.0 vs 15.1). On price, ads and device support 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. iFour Core sells 2 in-app purchases, starting at $5.99 per month. Onyx Physical Therapy asks for nothing beyond the download.

UpkeepUpdate frequency

iFour Core ships an update every 2 months, Onyx Physical Therapy every 9 months. The most recent releases landed on June 4, 2026 and September 20, 2026 respectively.

Scorecard3 real differences · 7 level
iFour Core versus Onyx Physical Therapy: the parameters behind the verdict, then further details
ParameteriFour CoreOnyx Physical Therapy
PriceFreeFree
Rating5.0 (28 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings28 — better—
Update frequencyEvery 2 months — betterEvery 9 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS11.0 — better15.1
Further details — not scored
Size39 MB43 MB
Age rating4+17+
Developerifour.life, LLCOnyx Physical Therapy and Wellness Inc.

In-app purchases

2 purchases

iFour Core

Subscriptions2
  • Monthly7 Days trial$5.991 Month
  • Annually7 Days trial$29.991 Year
None

Onyx Physical Therapy

No in-app purchases

Questions

Is iFour Core free?
iFour Core is free to download, with in-app purchases available.
Is Onyx Physical Therapy free?
Onyx Physical Therapy is free to download, with no in-app purchases.
Do iFour Core or Onyx Physical Therapy have ads?
Neither iFour Core nor Onyx Physical Therapy shows ads.
Which is updated more often, iFour Core or Onyx Physical Therapy?
iFour Core ships an update every 2 months, and Onyx Physical Therapy every 9 months. Most recently, iFour Core was updated on June 4, 2026 and Onyx Physical Therapy on September 20, 2026.

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