Comparison

GainFrame vs Rust Strength

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

Head to head
About

GainFrame

This app analyzes your progress photos to provide body fat estimates, muscle group insights, and personalized AI coaching based on your check-ins. It helps you visualize changes beyond the scale and track your fitness journey with guided photo capture and integration with health apps.

Highlights
  • Body fat estimates from photos
  • Muscle group analysis
  • AI Coach based on your data
  • Side-by-side photo comparisons
  • Guided pose templates
  • Integration with Apple Health, Hevy, Strava
Features
Read full description

See what’s actually changing in your physique. GainFrame turns progress photos into body-fat estimates, muscle-group insights, side-by-side comparisons, and an AI Coach grounded in your real check-ins—not generic fitness advice. FROM PHOTO TO PROOF • Compare any two check-ins side by side • See body-fat, weight, and physique-score changes together • Open an AI Deep Dive that explains what changed—and why • Review 12 muscle groups across front and back poses AN AI COACH THAT KNOWS YOUR DATA Ask Coach about your latest check-in, weight trend, training, sleep, or recovery. Responses use the data you choose to connect, so the guidance reflects your actual progress instead of a generic template. SEE MORE THAN THE SCALE • Body-fat estimates from progress photos • Physique scoring and muscle-group breakdowns • Precision estimates from multiple poses • BMI and FFMI trends • Future You physique projections • Weekly and monthly progress chapters BUILT FOR CONSISTENT CHECK-INS • Guided pose templates and photo alignment • Import existing photos from your camera roll • Organize every check-in in a visual timeline • Track streaks, milestones, and weight trajectory • Create shareable before-and-after cards CONNECTED TO YOUR ROUTINE Connect Apple Health, Hevy, and Strava to bring weight, workouts, cardio, sleep, HRV, and recovery into the same progress story. PRIVATE BY DESIGN Your progress-photo library is stored on your device, and no account is required to start tracking. When you choose an AI feature, the selected photos are securely processed for analysis and are not stored on GainFrame servers. HOW IT WORKS 1. Capture a check-in or import photos you already have 2. Get your visual progress read and body-composition estimates 3. Compare over time and ask Coach what to focus on next Start your next check-in and turn the work you’re already doing into progress you can see. IMPORTANT GainFrame is a fitness tracking tool, not a medical device. AI-generated estimates—including body-fat percentage, BMI, FFMI, muscle scores, and macro recommendations—are approximations based on photo analysis and should not be used for diagnosis or treatment. Consult a qualified healthcare professional before making health or fitness decisions. Powered by fatsecret nutrition API (www.fatsecret.com) Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Rust Strength

This app helps weightlifters determine the optimal weight for their next set based on previous performance and desired rep range. It also tracks runs with GPS, providing detailed metrics and progress summaries. Users can connect with friends, compete on leaderboards, and earn achievements.

Highlights
  • Smart weight suggestions for next lifting set
  • GPS running tracking with live map
  • Workout and run summaries with charts
  • Social feed and leaderboards for friends
  • Progress tracking with streaks and trophies
  • Rest timer with Lock Screen and Dynamic Island integration
  • Support for over 40 activities
Features
Read full description

Rust Strength answers the question every lifter has mid-workout: how much should I put on the bar for the next set? And now it records your runs too. Log a set with the weight, the reps, and how hard it felt on the RPE scale. Rust Strength estimates your one-rep max from that, then suggests a weight for your next set aimed at reaching failure inside the rep range you chose. Every suggestion is rounded to a weight the machine in front of you can actually be set to, and each machine keeps its own history, so a hotel gym doesn't throw off what it knows about your home gym. LIFTING Weight suggestions after every set, with a plain-English reason for each one. Every set from last time shown while you log, top set in bold. Over 200 exercises built in, or add your own. Search forgives typos. Bodyweight, assisted and timed exercises: more reps, less assistance, or a longer hold to beat. Presets, and a generator that builds a session from the equipment you have and the muscles you haven't trained this week. A rest timer that starts when you save a set, counting down on your Lock Screen and in the Dynamic Island with your next set. RUNNING Record runs with GPS, with your phone locked: live map, distance, pace, splits and steps. Your time, distance and pace on the Lock Screen and in the Dynamic Island. Auto-pause at lights, and optional spoken updates every mile or kilometer. A summary for every run with pace and elevation charts. Edit the title or trim the start and end afterwards. Weekly and monthly distance, a weekly goal, and your fastest mile, 5K, 10K, half marathon and marathon. Save a route, run it again and compare your attempts. Enter treadmill runs by hand. PROGRESS AND FRIENDS Streaks, consistency, volume, time trained and personal records. Every activity counts toward your streak, and planned rest days keep it alive. A body chart of the muscle groups you trained this week, and a progress chart for every exercise. Tiered trophies from Wood to Legend for lifts, running, steps and more, plus XP, levels and badges. Show two favorites next to your name. A feed of friends' sessions and runs that you can react to, and a leaderboard for streaks, weight lifted, workout time, distance run and more. Share a card after any workout or run, to Instagram, Messages or Photos. Track 40+ other activities, from pickleball to skiing. DESIGNED TO ASK FOR LITTLE No ads. No analytics. No tracking. Rust Strength asks for an email address and a password so your training syncs, and collects nothing it doesn't need. Location is used only for runs you record and privacy zones you set. Friends see a summary of a session, never the individual sets, and a run's map only if you share it, with the start and end always hidden. Steps are shared only if you turn that on. Export everything you've logged, or delete your account and all its data, from inside the app at any time. IMPORTANT Rust Strength is a training log, not medical or professional coaching advice. It suggests weights from the numbers you give it and knows nothing about your health, injuries or experience. Warm up, use your own judgement, and stop if something hurts. Be aware of your surroundings when you run. Talk to a doctor before starting a new training program. Privacy Policy: https://lindellrhett-gif.github.io/rust-strength/privacy.html Terms of Service: https://lindellrhett-gif.github.io/rust-strength/terms.html

Screenshots

GainFrame4 screens
Rust Strength4 screens

Verdict

The call

The clearest difference is in-app purchases: Rust Strength at none against GainFrame's 8. Rust Strength also leads on review sentiment (100% vs 88%). GainFrame's advantage is update cadence (every 4 days vs fortnightly) and ratings volume (75 vs 3). On price, rating, 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. GainFrame sells 8 in-app purchases, starting at $3.99 per 7 days. Rust Strength asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.9 for GainFrame against 5.0 for Rust Strength. That said, the two scores are not equally well evidenced: GainFrame has 75 ratings behind it against 3, so its average is the more settled of the two. Written reviews are what separate them: 88% of GainFrame's written reviews are positive against 100% of Rust Strength's.

UpkeepUpdate frequency

GainFrame ships an update every 4 days, Rust Strength fortnightly. The most recent releases landed on November 9, 2026 and November 10, 2026 respectively.

Scorecard5 real differences · 5 level
GainFrame versus Rust Strength: the parameters behind the verdict, then further details
ParameterGainFrameRust Strength
PriceFreeFree
Rating4.9 (75 ratings)5.0 (3 ratings) — better
Positive reviews88.5% of reviews100.0% of reviews — better
Number of ratings75 — better3
Update frequencyEvery 4 days — betterFortnightly
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad — betteriPhone
Requires iOS17.016.4 — better
Further details — not scored
Size244 MB42 MB
Age rating+412+
DeveloperMichael RodeRHETT JOHN LINDELL

Customer experience

GainFrame

All ratings72 ratings
Positive98.6%
Neutral0.0%
Negative1.4%
Written reviews26 reviews
Positive88.5%
Neutral0.0%
Negative11.5%

Rust Strength

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

In-app purchases

8 purchases

GainFrame

Subscriptions8
  • Pro Weekly$3.997 Days
  • Pro Monthly$5.991 Month
  • Pro Monthly$7.991 Month
Show 5 more
  • Pro Weekly$9.997 Days
  • Pro Yearly$39.991 Year
  • Pro Yearly7 Days trial$39.991 Year
  • Pro Annual Special Offer1 Year trial$49.991 Year
  • Pro Yearly$49.991 Year
None

Rust Strength

No in-app purchases

Questions

Is GainFrame free?
GainFrame is free to download, with in-app purchases available.
Is Rust Strength free?
Rust Strength is free to download, with no in-app purchases.
Which has better reviews, GainFrame or Rust Strength?
Rust Strength is rated higher. GainFrame averages 4.9 out of 5 from 75 ratings, while Rust Strength averages 5.0 from 3 ratings.
Do GainFrame or Rust Strength have ads?
Neither GainFrame nor Rust Strength shows ads.
Which is updated more often, GainFrame or Rust Strength?
GainFrame ships an update every 4 days, and Rust Strength fortnightly. Most recently, GainFrame was updated on November 9, 2026 and Rust Strength on November 10, 2026.

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