Comparison

Simple One vs JuggernautAI

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

Head to head
About

Simple One

This app helps you accurately determine your one-rep max (1RM) using multiple proven formulas. It provides reliable estimates to help you choose the right weights for your training, ensuring safer and more effective strength progression.

Highlights
  • Accurate one-rep max estimates
  • Multiple proven calculation formulas
  • Determine training weights
  • Fast and simple interface
  • Distraction-free design
Features
Read full description

Stop guessing your max. Train with confidence. Simple One Rep Max Calculator helps you understand how strong you really are — so every workout has a purpose. By calculating your one-rep max using multiple proven formulas, you get realistic numbers you can trust, not just a single estimate. Know your limits, choose the right weights, and progress safely — whether you’re pushing for new PRs or building strength over time. Why you’ll love it • Clear and reliable max lift estimates • Multiple formulas for better confidence • Training weights at the right intensity • Fast, simple, and distraction-free Less guessing. Better progress.

About

JuggernautAI

This app uses AI to create personalized strength training programs for powerlifting and powerbuilding. It adapts to your feedback and goals, optimizing volume, frequency, and exercise selection for maximum strength gains and recovery.

Highlights
  • AI-generated personalized workout plans
  • Powerlifting and Powerbuilding goal focus
  • Adaptive training based on real-time feedback
  • Optimized training frequency and volume
  • Exercise selection for weak points
  • Periodization strategy for fatigue management
Features
Read full description

Juggernaut Training Systems’ revolutionary A.I. strength training system has arrived on iOS. Subscribe to JuggernautAI to access all our coaching and get stronger than you can imagine with The Smartest Program for You. Designed by legendary coach Chad Wesley Smith with revolutionary technology by Tim Arnold, JuggernautAI is like having the best strength coach in the world with you during every workout in the gym. HOW IT WORKS JuggernautAI helps you reach your strength potential using our cutting edge technology - the JuggernautAI Powerlifting and Powerbuilding system - in an efficient and easy to use way; Decide on your goal of Powerlifting, to focus on building your Squat, Bench, and Deadlift, or Powerbuilding, to balance your focus between bodybuilding and strength training. Tell us about yourself, your level of experience, and your strength goals JuggernautAI will then design a unique individualized program tailored just for you with the use of expert technology As you progress, the system will continue to adapt your training plan based on your real-time individualized feedback, ensuring you continue to grow and achieve your strength goals. WHY IT WORKS Your JuggernautAI strength program is specifically tailored to your needs and includes; ◆◆ Individualized Volume Landmarks. Do enough training to advance but not so much that you can’t recover. ◆◆ Optimized Training Frequency. Decide how many days a week you want to train, and JuggernautAI will optimize when and how often you should Squat, Bench, and Deadlift. ◆◆ Personalized Periodization Strategy. JuggernautAI finds the best way to progress to ensure you maximize your training while also managing fatigue through a strategic phasic periodization plan. ◆◆ Exercise Selection for your Weak Points. JuggernautAI looks at your weak points and your strength in individual lifts to decide which exercises will be most effective in helping you improve. As a Powerbuilding user, you can also choose which body part to focus on to ensure your physique improves the way you want it to. ◆ Real-Time Feedback Your unique individualized program continues to adapt to your feedback with our Readiness Rating System, making adjustments to your program pre-session, intra-session, session to session, week to week, block to block, and program to program Subscribe to JuggernautAI and get the smartest program for you. ———- ABOUT JUGGERNAUT TRAINING SYSTEMS Juggernaut Training Systems is The Leader in Strength, having helped thousands of athletes from beginners to World Champions maximize their results and reach their goals. We deliver principle-based coaching through cutting-edge technology to help you get the best results of your life. Privacy Policy: https://www.jtsstrength.com/app-privacy-policy/ Terms of Use: https://www.jtsstrength.com/app-terms-of-use/

Screenshots

Simple One1 screens
JuggernautAI4 screens

Verdict

The call

The clearest difference is price: JuggernautAI at Free against Simple One's $0.99. JuggernautAI also leads on update cadence (every 4 days vs every 13 months) and ratings volume (5.7K vs 2). Simple One's advantage is in-app purchases (none vs 2). On ads and iOS requirement 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

JuggernautAI is free to download; Simple One costs $0.99 up front. JuggernautAI sells 1 in-app purchase, starting at $34.99 per month. Simple One asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

JuggernautAI holds the better App Store score, 4.8 against 4.5. That said, the two scores are not equally well evidenced: JuggernautAI has 5.7K ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 50% of Simple One's written reviews are positive against 73% of JuggernautAI's.

UpkeepUpdate frequency

Simple One ships an update every 13 months, JuggernautAI every 4 days. Both last shipped on October 20, 2026.

Scorecard8 real differences · 2 level
Simple One versus JuggernautAI: the parameters behind the verdict, then further details
ParameterSimple OneJuggernautAI
Price$0.99Free — better
Rating4.5 (2 ratings)4.8 (5.7K ratings) — better
Positive reviews50.0% of reviews72.7% of reviews — better
Number of ratings25.7K — better
Update frequencyEvery 13 monthsEvery 4 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaid — betterSubscription
DevicesiPhoneiPhone, iPad, iPod — better
Requires iOS16.015.6 — better
Further details — not scored
Size2 MB108 MB
Age rating17+17+
DeveloperAbove ASJuggernaut Apps

Customer experience

Simple One

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

JuggernautAI

All ratings5,655 ratings
Positive97.0%
Neutral1.2%
Negative1.7%
Written reviews216 reviews
Positive72.7%
Neutral4.2%
Negative23.1%

Bugs and requests

Simple One

Not enough reviews yet to summarise bugs or requests.

JuggernautAI

Reported bugs

3 issues
  • Clearing of workout history after each block
  • Issues with the auto-timer feature
  • Problems with selecting dates and times during setup

Requested features

4 requests
  • Integration with Apple Health or other fitness apps
  • More flexibility in scheduling and workout days
  • Improved exercise library and replacement options
  • Better tracking and history of past workouts

In-app purchases

None

Simple One

No in-app purchases

1 purchases

JuggernautAI

Subscriptions1
  • JuggernautAI Monthly2 variants$34.991 Month

Questions

Is Simple One free?
Simple One costs $0.99, with no in-app purchases.
Is JuggernautAI free?
JuggernautAI is free to download, with in-app purchases available.
Which has better reviews, Simple One or JuggernautAI?
JuggernautAI is rated higher. Simple One averages 4.5 out of 5 from 2 ratings, while JuggernautAI averages 4.8 from 5.7K ratings.
Do Simple One or JuggernautAI have ads?
Neither Simple One nor JuggernautAI shows ads.
Which is updated more often, Simple One or JuggernautAI?
Simple One ships an update every 13 months, and JuggernautAI every 4 days. Most recently, Simple One was updated on October 20, 2026 and JuggernautAI on October 20, 2026.

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