Comparison

Stronglifts 5x5 Workout Plan vs Flex

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

Head to head
About

Stronglifts 5x5 Workout Plan

This app guides you through a proven barbell strength training program with no guesswork. It plans every exercise, set, and weight for you, allowing you to focus on lifting and see consistent progress. Ideal for beginners or those returning to strength training.

Highlights
  • Proven 3x/week strength program
  • Automated progression
  • Guided workouts with timers
  • Progress charts
  • Simple interface
Features
Read full description

Get stronger with the world’s simplest, most proven barbell program: the 5×5 workout. No guesswork. Just follow along and see real results, in just 3 workouts a week. StrongLifts is made for lifters starting or returning to barbell strength training. The app removes all confusion and complexity by guiding you through every 5×5 workout. It plans every exercise, set, and weight so you always know exactly what to do. The time-tested 5×5 workout gets you stronger, week after week. No experience needed. ▸ Proven 3×/week strength program: Structured workouts, all planned for you. ▸ No guesswork: Fully automated progression for consistent strength gains. ▸ Just follow along: Simple interface with timers. Focus on lifting, not fiddling. ▸ Stay motivated. See your strength go up every week with clear progress charts. ▸ Easy to stick with. Simple, guided 3×/week program. No decisions, just results. Over 3 million lifters worldwide have started or restarted their strength journey with StrongLifts since 2007. The app has been featured and reviewed in the British Journal of Sports Medicine. StrongLifts is the best strength app, with more than 200,000 five-star reviews worldwide. StrongLifts is built on the classic 5×5 workout made famous by legends like Reg Park, Bill Starr, and Glenn Pendlay. For more than 70 years, the 5×5 workout has been proven to get new and returning lifters stronger, quickly and safely. Download StrongLifts today and join millions getting stronger. StrongLifts is free to download, but requires a subscription to use. All new users get a 7-day free trial for the yearly plan. Monthly and quarterly plans are also available without a free trial. Subscription renews automatically unless canceled at least 24 hours before the end of each period. Manage or cancel your subscription any time in your App Store account settings. https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Flex

This app helps strength training enthusiasts track their workouts. Create custom plans, log reps and weight, and monitor progress with a dashboard and rest timers. It syncs with Apple Health.

Highlights
  • Workout plan creation
  • Rep and weight tracking
  • Rest timers
  • Exercise progress monitoring
  • Apple Health sync
  • Customizable units (KG/LB)
Features
Read full description

Flex is a simple yet powerful workout tracker that has been designed for anyone who engages in strength training. Effortlessly create workout plans, track workouts, and browse previous workouts all with a simple and intuitive user interface. Features: - Useful dashboard that shows all time statistics, recent workouts, and the next workout in your current workout cycle - Create custom workout plans for any kind of program (such as Starting Strength or StrongLifts 5×5) - Duplicate existing workout plans which make it easy to create similar plans with slight variations - Track reps and weight performed for each exercise during a workout and compare them the last workout - great for pushing yourself. - Automatic and customisable rest timers that are triggered automatically when completing each set - Comprehensive exercise list to choose from when creating workouts - Create custom exercises for your workouts - Choose between metric (KG) and imperial (LB) units for sets - View your complete chronological workout history - Keep track of your exercise progress and personal bests - Automatically sync workouts with Apple Health

Screenshots

Stronglifts 5x5 Workout Plan4 screens
Flex4 screens

Verdict

The call

The clearest difference is rating: Stronglifts 5x5 Workout Plan at 4.9 against Flex's 4.2. Stronglifts 5x5 Workout Plan also leads on ratings volume (77K vs 5). Flex's advantage is in-app purchases (none vs 10) and review sentiment (75% vs 63%). On price, update cadence, 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. Stronglifts 5x5 Workout Plan sells 8 in-app purchases, starting at $4.99 per 7 days. Flex asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Stronglifts 5x5 Workout Plan holds the better App Store score, 4.9 against 4.2. That said, the two scores are not equally well evidenced: Stronglifts 5x5 Workout Plan has 77K ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 63% of Stronglifts 5x5 Workout Plan's written reviews are positive against 75% of Flex's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Stronglifts 5x5 Workout Plan ships an update every 2 weeks, Flex fortnightly. The most recent releases landed on November 6, 2026 and November 1, 2026 respectively.

Scorecard6 real differences · 4 level
Stronglifts 5x5 Workout Plan versus Flex: the parameters behind the verdict, then further details
ParameterStronglifts 5x5 Workout PlanFlex
PriceFreeFree
Rating4.9 (77K ratings) — better4.2 (5 ratings)
Positive reviews62.6% of reviews75.0% of reviews — better
Number of ratings77K — better5
Update frequencyEvery 2 weeks — betterFortnightly
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPod
Requires iOS18.014.0 — better
Further details — not scored
Size172 MB5 MB
Age rating4+4+
DeveloperStrongLiftsDino Constantinou

Customer experience

Stronglifts 5x5 Workout Plan

All ratings76,863 ratings
Positive97.6%
Neutral1.1%
Negative1.3%
Written reviews1,428 reviews
Positive62.6%
Neutral3.9%
Negative33.5%

Flex

All ratings5 ratings
Positive80.0%
Neutral0.0%
Negative20.0%
Written reviews12 reviews
Positive75.0%
Neutral0.0%
Negative25.0%

Bugs and requests

Stronglifts 5x5 Workout Plan

Reported bugs

3 issues
  • Workout data loss and reset issues
  • Inconsistent Apple Watch connectivity
  • Inability to edit or delete custom exercises

Requested features

5 requests
  • Ability to customize core exercises
  • Menstrual cycle tracking and programming
  • More pre-built program options
  • Integration with other fitness apps and devices
  • Recommended meal plans and nutrition guidance

Flex

Not enough reviews yet to summarise bugs or requests.

In-app purchases

8 purchases

Stronglifts 5x5 Workout Plan

Subscriptions6
  • Pro Weekly$4.997 Days
  • Pro Monthly2 variants$11.991 Month
  • Pro Quarterly2 variants$29.993 Months
Show 3 more
  • Pro Yearly$59.991 Year
  • Pro Yearly1 Year trial$59.991 Year
  • Pro Yearly7 Days trial$59.991 Year
One-time2
  • StrongLifts Pro 5 Years$199.99
  • StrongLifts Pro 5 Years$239.99
None

Flex

No in-app purchases

Questions

Is Stronglifts 5x5 Workout Plan free?
Stronglifts 5x5 Workout Plan is free to download, with in-app purchases available.
Is Flex free?
Flex is free to download, with no in-app purchases.
Which has better reviews, Stronglifts 5x5 Workout Plan or Flex?
Stronglifts 5x5 Workout Plan is rated higher. Stronglifts 5x5 Workout Plan averages 4.9 out of 5 from 77K ratings, while Flex averages 4.2 from 5 ratings.
Do Stronglifts 5x5 Workout Plan or Flex have ads?
Neither Stronglifts 5x5 Workout Plan nor Flex shows ads.
Which is updated more often, Stronglifts 5x5 Workout Plan or Flex?
Stronglifts 5x5 Workout Plan ships an update every 2 weeks, and Flex fortnightly. Most recently, Stronglifts 5x5 Workout Plan was updated on November 6, 2026 and Flex on November 1, 2026.

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