Comparison

RunGap vs Z2/4×4 Trainer

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

Head to head
About

RunGap

Consolidate workout data from over 50 fitness services into one app. Access, share, and export your training history with detailed statistics, charts, and gear tracking. Integrates with popular devices and platforms.

Highlights
  • Syncs data from 50+ fitness services
  • Consolidates training history
  • Detailed statistics and charts
  • Interactive maps and activity details
  • Track shoe, bike, and gear usage
  • Geotag photos and videos
Features
Read full description

The most well-connected Workout Data manager on the App Store with support for 50 of the most popular apps and services. Get your complete training history and take control of your workout data. Keep all your workout details from popular services including Apple Watch, Polar, Garmin, Coros, Peloton, Strava, Runtastic, Suunto, adidas, SportsTracker, Apple Health, Zwift, Rouvy and many others on your iPhone or iPad for instant access anytime. Easily share, backup and export your workouts as you like (requires "Swag Bag" subscription available as in-app purchase). Unattended background operation. RunGap can both read and write workouts from and to Health including route maps, heart rate and distance. View statistics and interactive charts, maps and details for individual workouts. Browse your favorite tracks and compare past results. Easily track your shoe, bike and other gear usage. Geotag photos and videos related to an activity. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ PLEASE NOTE: If you have any issues, consider contacting support instead of giving a negative rating - most times your issues can be solved or answered. A rating will not get your app back to work, but the support can help - simply use the integrated "Online Support" function.

About

Z2/4×4 Trainer

Features
Read full description

Z2/4×4 Trainer turns the two most effective endurance methods — easy Zone 2 base work and high-intensity Norwegian 4×4 intervals — into a simple daily plan built around YOUR heart rate. WHAT YOU GET • Daily and weekly Zone 2 prescriptions at 60–70% of your max heart rate to build your aerobic base. • Norwegian 4×4 sessions: four 4-minute intervals at 85–95% of max heart rate, with 3-minute recoveries — the protocol used to boost VO2 max. • Weekly health-maintenance and weight-loss targets to keep you consistent. • Personalized zones from your max heart rate (220 − age), which you can override if you know your true max. WORKS WITH APPLE HEALTH • Pull in your heart rate, resting heart rate, active energy, body weight, and past workouts — or enter everything manually. Your choice. • Completed Zone 2 and 4×4 workouts are saved back to Apple Health so all your training lives in one place. IPHONE + APPLE WATCH • Plan and review on iPhone; train with your zones on your wrist. PRIVATE BY DESIGN • 100% on-device. No account, no sign-up, no server. • Nothing you enter or that we read from Apple Health ever leaves your device. • No ads, no analytics, no tracking, no third-party SDKs. • Your Health data is never used for advertising — ever. WHO IT'S FOR • Runners, cyclists, rowers, and anyone doing cardio who wants structure instead of guesswork. • Beginners building a base and experienced athletes adding VO2-max work. FREE + AN OPTIONAL ONE-TIME UPGRADE • Everything above is free: guided workouts on iPhone and Apple Watch, plans, zones, Apple Health sync. • One optional one-time purchase (Pro) unlocks the deeper coaching analysis: full readiness breakdown, overtraining guard, adaptive weekly progression, VO2-max trend, and CSV/JSON export. No subscription. Z2/4×4 Trainer is a fitness and training tool, not a medical device. It does not diagnose, treat, or prevent any disease. Talk to a healthcare professional before starting a new exercise program.

Screenshots

RunGap4 screens
Z2/4×4 Trainer4 screens

Verdict

The call

The clearest difference is iOS requirement: RunGap at 16 against Z2/4×4 Trainer's 18.0. On price, update cadence, ads and in-app purchases 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. RunGap sells 2 in-app purchases, starting at $4.99 per 3 months and Z2/4×4 Trainer sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

RunGap ships an update every 2 weeks, Z2/4×4 Trainer every 3 weeks. The most recent releases landed on November 6, 2026 and October 31, 2026 respectively.

Scorecard1 real difference · 9 level
RunGap versus Z2/4×4 Trainer: the parameters behind the verdict, then further details
ParameterRunGapZ2/4×4 Trainer
PriceFreeFree
Rating4.8 (5.9K ratings) — better—
Positive reviews77.0% of reviews—
Number of ratings5.9K — better—
Update frequencyEvery 2 weeks — betterEvery 3 weeks
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone, Apple Watch
Requires iOS16 — better18.0
Further details — not scored
Size14 MB5 MB
Age rating12+4+
DeveloperCTRL-NChenfei Chu

Bugs and requests

RunGap

Reported bugs

3 issues
  • App crashes or freezes
  • Syncing issues with certain platforms
  • Incorrect data transfer or formatting

Requested features

4 requests
  • Improved user interface and navigation
  • Automatic background syncing
  • Integration with more fitness platforms
  • Offline data access and editing

Z2/4×4 Trainer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

RunGap

Subscriptions2
  • Quarterly Swag Bag$4.993 Months
  • Annual Swag Bag$14.991 Year
1 purchases

Z2/4×4 Trainer

One-time1
  • Z2/4×4 Pro (Lifetime)$14.99

Questions

Is RunGap free?
RunGap is free to download, with in-app purchases available.
Is Z2/4×4 Trainer free?
Z2/4×4 Trainer is free to download, with in-app purchases available.
Do RunGap or Z2/4×4 Trainer have ads?
Neither RunGap nor Z2/4×4 Trainer shows ads.
Which is updated more often, RunGap or Z2/4×4 Trainer?
RunGap ships an update every 2 weeks, and Z2/4×4 Trainer every 3 weeks. Most recently, RunGap was updated on November 6, 2026 and Z2/4×4 Trainer on October 31, 2026.

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