Comparison

GymNext Flex Timer vs Interval(x)

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

Head to head
About

GymNext Flex Timer

This app offers advanced interval training timing with customizable modes and the ability to control an external LED display. It integrates with wearables and heart rate monitors for a comprehensive workout experience.

Highlights
  • Control external LED displays
  • Multiple customizable timer modes (Tabata, EMOM, etc.)
  • Save and recall favorite workouts
  • Apple Watch control
  • Audio sync with music
  • Heart rate monitor integration
  • Control multiple LED displays
Features
Read full description

Meet the future of interval training. GymNext Flex Timer is the only timer app that combines powerful workout programming with control of large, wall-mounted LED displays—giving you the best of both worlds. Traditional gym timers rely on clunky remotes and are difficult to use. Mobile apps are flexible, but hard to see across the room. Flex Timer solves both. Build and control your workouts from your phone while displaying them on bright, easy-to-read LED screens anywhere in your gym. Perfect for HIIT, CrossFit, circuits, bootcamps, boxing, MMA, strength training, and more. Features: • Use the app on its own or connect to GymNext LED displays for maximum visibility • Core timer modes include Count Up/Down, Round, Tabata, EMOM, Mixed Intervals, and Sets with Rest • Plan your personal workouts or full classes in advance—everything ready in one tap • Share timers with athletes and trainers instantly using simple links • Save workouts to your library for quick access • Control your timer from Apple Watch—completely hands-free • Smart audio sync keeps your music and timer cues perfectly aligned • Connect multiple Bluetooth heart rate monitors and track performance in real time • Set custom heart rate zones for better training feedback • Control multiple timers across your gym at the same time • Run different workouts simultaneously for group training • Reliable Bluetooth control with no line-of-sight limitations “This will eventually become the standard for all gyms” – Garage Gym Reviews “All our coaches love the clock” – CrossFit Barrie “We love it to death” – Wolverine Strength & Conditioning Download Flex Timer and upgrade the way you train. We’re always improving. Have feedback? Reach us at support@gymnext.com

About

Interval(x)

An open-source interval timer designed for precision and privacy. Configure work and rest periods with millisecond accuracy for training or daily routines. It offers a transparent, data-free experience for users who value control and simplicity.

Highlights
  • Open Source Transparency
  • Zero Data Collection
  • Millisecond Interval Precision
  • Customizable Work/Rest Periods
  • Lightweight and Power-Efficient
  • Privacy-First Design
Features
Read full description

Interval(x): Open Source Precision for Engineers Engineered for precision and transparency, Interval(x) is the ultimate interval timer for those who value control, simplicity, and privacy. Built by engineers for engineers, this app delivers unmatched timing accuracy without the frills—or the data collection. Why Engineers Love Interval(x): Open Source: Fully transparent and modifiable—because we believe in community-driven development. Zero Data Collection: Your data is yours. Interval(x) operates without tracking, analytics, or unnecessary permissions. Customizable and Precise: Configure work/rest intervals down to the millisecond to match your exact training needs. Efficient Design: Lightweight, power-efficient, and designed for those who demand performance. Privacy-First, Community-Driven Interval(x) is a privacy-focused tool that doesn't track your activity or collect your data. Its open-source codebase is available for review and contributions, ensuring transparency and trust. Whether you're training for endurance, strength, or just optimizing your daily routine, Interval(x) provides the precision and simplicity you need without sacrificing your privacy. Download Interval(x) today and experience fitness on your terms. Power your workouts with open source freedom and engineering-grade accuracy.

Screenshots

GymNext Flex Timer4 screens
Interval(x)3 screens

Verdict

The call

The clearest difference is in-app purchases: Interval(x) at none against GymNext Flex Timer's 2. Interval(x) also leads on rating (5.0 vs 4.8). GymNext Flex Timer's advantage is ratings volume (2.1K vs 1) and device support (4 vs 2). On price, update cadence, ads and monetization model 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. GymNext Flex Timer sells 2 in-app purchases, starting at $8.99 per month. Interval(x) asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Interval(x) holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: GymNext Flex Timer has 2.1K ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

GymNext Flex Timer ships an update every 3 weeks, Interval(x) every 10 days. The most recent releases landed on September 22, 2026 and September 18, 2026 respectively.

Scorecard5 real differences · 5 level
GymNext Flex Timer versus Interval(x): the parameters behind the verdict, then further details
ParameterGymNext Flex TimerInterval(x)
PriceFreeFree
Rating4.8 (2.1K ratings)5.0 (1 ratings) — better
Positive reviews72.4% of reviews—
Number of ratings2.1K — better1
Update frequencyEvery 3 weeksEvery 10 days — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreeFree
DevicesiPhone, iPad, iPod, Apple Watch — betteriPhone, iPad
Requires iOS15.0 — better18.1
Further details — not scored
Size185 MB2 MB
Age rating4+4+
DeveloperHomick EnterprisesShapeHaven Innovations LLC

Customer experience

GymNext Flex Timer

All ratings2,119 ratings
Positive96.6%
Neutral1.1%
Negative2.4%
Written reviews170 reviews
Positive72.4%
Neutral5.9%
Negative21.8%

Interval(x)

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

GymNext Flex Timer

Reported bugs

2 issues
  • Saved timers not consistently loading
  • Segmented timers not saving properly

Requested features

4 requests
  • Watch app integration for remote control
  • Background audio playback when app is closed
  • Customizable voice options
  • Lap timer functionality

Interval(x)

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

GymNext Flex Timer

Subscriptions2
  • Flex Timer Pro Monthly7 Days trial$8.991 Month
  • Flex Timer Pro Yearly1 Month trial$79.991 Year
None

Interval(x)

No in-app purchases

Questions

Is GymNext Flex Timer free?
GymNext Flex Timer is free to download, with in-app purchases available.
Is Interval(x) free?
Interval(x) is free to download, with no in-app purchases.
Which has better reviews, GymNext Flex Timer or Interval(x)?
Interval(x) is rated higher. GymNext Flex Timer averages 4.8 out of 5 from 2.1K ratings, while Interval(x) averages 5.0 from 1 ratings.
Do GymNext Flex Timer or Interval(x) have ads?
Neither GymNext Flex Timer nor Interval(x) shows ads.
Which is updated more often, GymNext Flex Timer or Interval(x)?
GymNext Flex Timer ships an update every 3 weeks, and Interval(x) every 10 days. Most recently, GymNext Flex Timer was updated on September 22, 2026 and Interval(x) on September 18, 2026.

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