Comparison

Seconds Pro Interval Timer vs Norwegian 4x4 Protocol

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

Head to head
About

Seconds Pro Interval Timer

This interval timer app is designed for high-intensity interval training (HIIT), Tabata, and circuit training workouts. It features a large, color-coded display, customizable interval names, and background operation. It also integrates with Apple Health to track your fitness data.

Highlights
  • Full screen colored display
  • Templates for HIIT, Tabata, Circuit Training
  • Speaks interval names and provides warnings
  • Assign music per interval
  • Runs in background
  • Share interval timers
  • Apple Health integration
Features
Read full description

Seconds Pro is an interval timer for HIIT, Tabata, EMOM, circuits and any workout built from timed intervals. It calls each interval out loud, keeps running with the screen off, and runs on iPhone, iPad and Apple Watch. Apple has featured it, and Joe Wicks, The Body Coach, has said it is the fitness app he uses more than any other. BUILD ANY WORKOUT - Start from a HIIT, Tabata or circuit template, or build a timer from scratch with sets, rounds and intervals of different lengths. - Chain timers into one compound timer, so a warm-up flows into the main set and then a cool-down. - Color-code every interval so you know what is coming before the beep. - Share a timer with a friend in one tap. HEAR IT, DON'T WATCH IT - Voice cues call out each interval by name and warn you before the next one starts. - Beeps and bells are there too if you would rather not be talked at. - Play your own music, per timer or per interval. Cues duck the music and it comes back up when they are done. - The timer keeps going in the background while you use other apps or the screen sleeps. ON THE GYM FLOOR - A full-screen, color-coded display you can read from across the room, in portrait or landscape. On iPad it uses the whole screen. - A lock button stops a stray tap from pausing your set. APPLE WATCH - Seconds Pro runs on the watch by itself, so the phone can stay in the locker. Timers you build on the phone sync to the wrist, and Quick Intervals builds a basic circuit on the watch itself. MORE TIMERS - A stopwatch that marks your best and worst laps. - A countdown timer with five preset durations (three on Apple Watch). APPLE HEALTH - Save workouts and mindful sessions to Health. With a heart rate monitor connected, Seconds Pro reads your body measurements and year of birth from Health to estimate calories burned. PAID ONCE, NOTHING TO UNLOCK - Seconds Pro is paid for up front. Every feature is included and every timer you make can be run as many times as you like. SECONDS AND SECONDS PRO - Seconds is the free version of this app. It has the same features, but each timer locks after one run until a single in-app purchase unlocks it. The two are separate products and a purchase in one does not carry over to the other. If you bought Seconds Pro, download Seconds Pro. If you bought the unlock in Seconds, download Seconds and use Restore Purchases.

About

Norwegian 4x4 Protocol

This app guides you through the effective Norwegian 4x4 interval training method to boost cardiovascular performance and endurance. It features a precision timer, heart rate zone tracking, and progress monitoring for scientifically proven results.

Highlights
  • Precision 4min work / 3min rest cycles
  • Heart rate zone tracking (90-95% max HR)
  • VO2 Max improvement tracking
  • Multiple HIIT workout protocols
  • Progress monitoring
  • Universal cardio training support
  • Offline functionality
Features
Read full description

Norwegian 4x4 HIIT Timer — Interval Training & VO2 Max BOOST VO2 MAX WITH NORWEGIAN 4X4 PROTOCOL WORKOUTS Train smarter with the Norwegian 4x4 protocol, one of the most studied HIIT methods for improving cardiovascular performance and endurance. A precise, distraction-free timer guides every interval so you can focus on the effort. KEY FEATURES: - Norwegian 4x4 Timer - Precision 4min work / 3min rest cycles - Heart Rate Training - Track 90-95% max HR zones - VO2 Max Improvement - Scientifically proven results - HIIT Interval Timer - Multiple workout protocols - Progress Tracking - Monitor your fitness transformation - Universal Training - Running, cycling, rowing, any cardio, you name it - Offline Ready - No internet required during workouts - Haptics Feedback and Vibrations - Countdown before the start - Customizable Warmup session length - Customizable Cooldown session length WHAT IS NORWEGIAN 4 BY 4 TRAINING? The Norwegian 4x4 protocol is a revolutionary HIIT method featuring: - 4 intervals of 4 minutes at 90-95% max heart rate - 3 minutes active recovery between intervals - Proven results: Increase VO2 max by up to 10% in 8 weeks - Elite approved: Used by professional athletes worldwide WHY CHOOSE NORWEGIAN 4X4 INTERVAL TRAINING? - PROVEN RESULTS: Sports science research shows significant cardiovascular improvements - BEGINNER FRIENDLY: Complete guide for Norwegian 4x4 workout beginners - CUSTOMIZABLE: Adapt the Norwegian 4 x 4 protocol to your fitness level - COMPREHENSIVE: Includes warm-up, cool-down, and recovery protocols - VALIDATED: Mention in Tim Ferriss' Blog PERFECT FOR: - Athletes seeking performance gains with Norwegian 4x4 workouts - Fitness enthusiasts wanting efficient HIIT interval training - Anyone improving cardiovascular health through proven protocols - Runners, cyclists, rowers using Norwegian 4x4 interval training HOW OFTEN NORWEGIAN 4X4? - Our app includes guidance on optimal training frequency and recovery for maximum VO2 max gains. START YOUR NORWEGIAN 4X4 TRANSFORMATION Join thousands who have revolutionised their fitness with the Norwegian 4x4 protocol training. Download the ultimate Norwegian 4x4 workout app now! Download today and start training with the Norwegian 4x4.

Screenshots

Seconds Pro Interval Timer4 screens
Norwegian 4x4 Protocol4 screens

Verdict

The call

The clearest difference is review sentiment: Seconds Pro Interval Timer at 80% against Norwegian 4x4 Protocol's 27%. Seconds Pro Interval Timer also leads on rating (4.8 vs 4.3) and ratings volume (12K vs 50). Norwegian 4x4 Protocol's advantage is price ($5.99 vs $7.99). On update cadence, ads, in-app purchases 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

Seconds Pro Interval Timer costs $7.99 and Norwegian 4x4 Protocol $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Seconds Pro Interval Timer holds the better App Store score, 4.8 against 4.3. That said, the two scores are not equally well evidenced: Seconds Pro Interval Timer has 12K ratings behind it against 50, so its average is the more settled of the two. Written reviews point the same way: 80% of Seconds Pro Interval Timer's written reviews are positive against 27% of Norwegian 4x4 Protocol's.

UpkeepUpdate frequency

Seconds Pro Interval Timer ships an update fortnightly, Norwegian 4x4 Protocol every 3 weeks. The most recent releases landed on October 14, 2026 and October 9, 2026 respectively.

Scorecard5 real differences · 6 level
Seconds Pro Interval Timer versus Norwegian 4x4 Protocol: the parameters behind the verdict, then further details
ParameterSeconds Pro Interval TimerNorwegian 4x4 Protocol
Price$7.99$5.99 — better
Rating4.8 (12K ratings) — better4.3 (50 ratings)
Positive reviews79.7% of reviews — better26.7% of reviews
Number of ratings12K — better50
Update frequencyFortnightly — betterEvery 3 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
Best chart rank#8 — better#171
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPad
Requires iOS18.017.6 — better
Further details — not scored
Size94 MB5 MB
Age rating4+4+
DeveloperRunloop LtdNikita Yampolski

Customer experience

Seconds Pro Interval Timer

All ratings12,104 ratings
Positive94.7%
Neutral1.9%
Negative3.4%
Written reviews1,520 reviews
Positive79.7%
Neutral6.0%
Negative14.3%

Norwegian 4x4 Protocol

All ratings50 ratings
Positive80.0%
Neutral6.0%
Negative14.0%
Written reviews15 reviews
Positive26.7%
Neutral33.3%
Negative40.0%

Bugs and requests

Seconds Pro Interval Timer

Reported bugs

4 issues
  • Intervals randomly pausing or skipping
  • Music volume issues when launching the app
  • Inconsistent audio cues and countdown
  • Sync issues between devices

Requested features

6 requests
  • Ability to lock Apple Watch screen
  • Option to see more than just the next exercise
  • Fractional time settings (e.g. 7.74 seconds)
  • More voice/audio customization options
  • Improved sync between iPhone and iPad
Show 1 more
  • Calendar integration to track workouts

Norwegian 4x4 Protocol

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Seconds Pro Interval Timer

No in-app purchases

None

Norwegian 4x4 Protocol

No in-app purchases

Questions

Is Seconds Pro Interval Timer free?
Seconds Pro Interval Timer costs $7.99, with no in-app purchases.
Is Norwegian 4x4 Protocol free?
Norwegian 4x4 Protocol costs $5.99, with no in-app purchases.
Which has better reviews, Seconds Pro Interval Timer or Norwegian 4x4 Protocol?
Seconds Pro Interval Timer is rated higher. Seconds Pro Interval Timer averages 4.8 out of 5 from 12K ratings, while Norwegian 4x4 Protocol averages 4.3 from 50 ratings.
Do Seconds Pro Interval Timer or Norwegian 4x4 Protocol have ads?
Neither Seconds Pro Interval Timer nor Norwegian 4x4 Protocol shows ads.
Which is updated more often, Seconds Pro Interval Timer or Norwegian 4x4 Protocol?
Seconds Pro Interval Timer ships an update fortnightly, and Norwegian 4x4 Protocol every 3 weeks. Most recently, Seconds Pro Interval Timer was updated on October 14, 2026 and Norwegian 4x4 Protocol on October 9, 2026.
Which is more popular, Seconds Pro Interval Timer or Norwegian 4x4 Protocol?
Seconds Pro Interval Timer currently peaks at #8 in the App Store charts, and Norwegian 4x4 Protocol at #171. Chart position reflects recent download velocity rather than total install base.

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