Comparison

FlexPro Grip vs MASS Monster

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

Head to head
About

FlexPro Grip

This app works with a specialized device to create customized training programs for baseball pitchers. It measures baseline strength and endurance to improve pitching performance, reduce injury risk, and accelerate recovery. Track your progress with saved workout history.

Highlights
  • Customized training protocols
  • Strength, endurance, and RPD testing
  • Objective data measurements
  • Injury risk reduction
  • Performance enhancement
  • Workout history tracking
Features
Read full description

OVERVIEW: The FlexPro Grip app is to be used along with the FlexPro Grip device. Designed primarily for baseball pitchers, the FlexPro Grip app provides customized training protocols to be performed on the FlexPro Grip device to improve the strength, endurance and explosiveness of the muscles and tendons from your fingertips through your elbow that most impact pitching performance. There is no guesswork. All data measurements are objective. The result: reduce the chance of tearing your UCL improve your spin rate increase your pitch movement throw harder enhance your command last longer in games recover faster after you throw accelerate your rehab if you are recovering from a UCL injury / forearm strain HOW APP WORKS: The app first guides you through a Strength, Endurance, and / or Rate of Force Development test to measure your baseline levels. Then, the app prescribes you with customized training protocols that specify the amount of force to apply, hold times, and the number of sets, reps, exercises to perform to help you make rapid gains in both your health and pitching performance. All workouts are saved to your History so you can track your progress at any time. NO MEDICAL ADVICE: The protocols are intended to provide recommendations but do not constitute medical advice. As with any form of sports or physical training, seek professional medical advice prior to initiating use.

About

MASS Monster

This app provides structured training guidance and daily accountability to help users build muscle, improve routines, and stay motivated. It fosters community support through challenges and rewards consistency, offering a system for building lasting fitness habits.

Highlights
  • Structured training guidance
  • Daily accountability
  • Progress tracking
  • Community motivation
  • Rewards and milestones
  • Clean interface
Features
Read full description

Build muscle with a workout planner, gym tracker, accountability check-ins, and a fitness community built around consistency. MASS Monster turns your goal into a repeatable training system. Choose a workout split, follow your current training day, organize sets and reps, and see what comes next on your calendar. When motivation drops, daily accountability, progress signals, and community support help you keep moving. PLAN YOUR TRAINING • Choose a workout plan or build a custom split • Organize training days, exercises, sets, and reps • Keep your current workout and next action easy to find • Use lift guides and courses when you need direction TRACK WORKOUTS AND PROGRESS • Record gym check-ins or choose Home Workout • Use accountability check-ins to make consistency visible • Review your workout history from the calendar • Build momentum through repeatable actions TRAIN WITH COMMUNITY SUPPORT • Join fitness community chat • Share workout splits and training ideas • Connect with members who understand the work • Post optional workout media and check-in stories EARN REWARDS FOR CONSISTENCY • Earn accountability points through eligible actions • Reach milestones and unlock eligible rewards • Turn disciplined training into visible progress LEARN AS YOU GO • Explore courses for muscle growth, fueling, and mindset • Use exercise guidance to train with more clarity • Explore free courses and lift guidance that show what to do next MASS Monster is for people who want more than random workouts. It brings workout planning, training logs, gym accountability, fitness motivation, community, education, and rewards into one place so you can build muscle and stay consistent. All app features and courses are free. Some features require an account, internet connection, location access, age eligibility, consent, or coach approval. Accountability requires a fresh foreground location when opened and when a check-in is submitted. Gym check-ins use it to verify proximity; Home Workout check-ins use it for submission validation and do not store device or gym coordinates. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ MASS Monster Terms of Service: https://massmonster.life/pages/mass-monster-terms-of-service-eula Privacy Policy: https://massmonster.life/policies/privacy-policy

Screenshots

FlexPro Grip3 screens
MASS Monster4 screens

Verdict

The call

The clearest difference is rating: MASS Monster at 5.0 against FlexPro Grip's 4.1. MASS Monster also leads on review sentiment (100% vs 67%). FlexPro Grip's advantage is in-app purchases (none vs 2) and ratings volume (27 vs 9). 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. MASS Monster sells 2 in-app purchases, starting at $19.99 per month. FlexPro Grip asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

MASS Monster holds the better App Store score, 5.0 against 4.1. Both are backed by a comparable volume of ratings — 27 and 9 respectively. Written reviews point the same way: 67% of FlexPro Grip's written reviews are positive against 100% of MASS Monster's.

UpkeepUpdate frequency

FlexPro Grip ships an update every 8 days, MASS Monster weekly. The most recent releases landed on October 30, 2026 and October 12, 2026 respectively.

Scorecard5 real differences · 5 level
FlexPro Grip versus MASS Monster: the parameters behind the verdict, then further details
ParameterFlexPro GripMASS Monster
PriceFreeFree
Rating4.1 (27 ratings)5.0 (9 ratings) — better
Positive reviews66.7% of reviews100.0% of reviews — better
Number of ratings27 — better9
Update frequencyEvery 8 daysWeekly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPod — betteriPhone
Requires iOS15.1 — better16.4
Further details — not scored
Size93 MB209 MB
Age rating4+12+
DeveloperFlexProGripTylor Vandenbroeke

Customer experience

FlexPro Grip

All ratings27 ratings
Positive77.8%
Neutral0.0%
Negative22.2%
Written reviews9 reviews
Positive66.7%
Neutral0.0%
Negative33.3%

MASS Monster

All ratings9 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

FlexPro Grip

No in-app purchases

2 purchases

MASS Monster

Subscriptions2
  • MASS Elite$19.991 Month
  • MASS Pro$49.991 Month

Questions

Is FlexPro Grip free?
FlexPro Grip is free to download, with no in-app purchases.
Is MASS Monster free?
MASS Monster is free to download, with in-app purchases available.
Which has better reviews, FlexPro Grip or MASS Monster?
MASS Monster is rated higher. FlexPro Grip averages 4.1 out of 5 from 27 ratings, while MASS Monster averages 5.0 from 9 ratings.
Do FlexPro Grip or MASS Monster have ads?
Neither FlexPro Grip nor MASS Monster shows ads.
Which is updated more often, FlexPro Grip or MASS Monster?
FlexPro Grip ships an update every 8 days, and MASS Monster weekly. Most recently, FlexPro Grip was updated on October 30, 2026 and MASS Monster on October 12, 2026.

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