Viking 4x4 vs Boreas: Which Norwegian 4x4 App Fits You?

Updated October 2026. Reviewed quarterly.

Boreas is the best-known dedicated Norwegian 4x4 timer on the App Store, and it's free and well made. Viking 4x4 covers the same timing and guidance, then adds the measurement layer: per-interval heart rate reports and 60-second heart rate recovery trends. Which one fits depends on whether you want a stopwatch or a scoreboard.

Viking 4x4

Price
First 4x4 free, then $6.99/mo or $29.99/yr
Apple Watch live heart rate
Yes — Watch app auto-launches
Other heart rate sensors
Via Apple Health
Per-interval report
Peak HR, HR at +60s, HRR-60
60-second HR recovery (HRR-60) per interval
Yes
Recovery trend across sessions
Recovery Score (last 12 sessions)
Reminders & streaks
No
Voice coaching
Yes
Apple Health sync
Yes

Boreas

Price
Free
Apple Watch live heart rate
Yes (basic)
Other heart rate sensors
No
Per-interval report
No
60-second HR recovery (HRR-60) per interval
No
Recovery trend across sessions
No
Reminders & streaks
No
Voice coaching
Interval cues
Apple Health sync
Yes

Feature comparison as of October 2026, based on public App Store listings.

Choose Boreas if…

You want a free, clean timer with basic Apple Watch heart rate and HealthKit saving, and you don't care about analyzing the workout afterward. It does that job well.

Choose Viking 4x4 if…

You're doing the 4x4 to move a number — VO2 max — and you want evidence it's moving: interval-by-interval peak heart rate, time in the 85–95% zone, and recovery trends that show your heart adapting week over week.

SKÅL!

Your heart. Stronger. Provably.

Download on theApp StoreFree download · First 4x4 free

Your first 4x4 is free · iPhone · Apple Watch companion