saavu.
Heat. Cold. Thrive.

The wellness app that proves
sauna is changing your body.

Track heart rate, HRV, and recovery through every round of heat and cold, right from your wrist. See your wellness as a face, not a spreadsheet. Find saunas nearby.


Most people feel better
after a sauna. Saavu shows you why.

You step out of the heat. The world feels softer. Your breathing slows. Maybe you sleep a little deeper that night. Saavu is the app that connects those feelings to what is actually happening in your body, and remembers, so the next week you can do it again with intent.

No spreadsheets. No clinical dashboards. Just your watch, your phone, and a quiet log of how your body is changing.

The smoke arrives. Your body changes. Saavu remembers.
9:41●●● ● ▮
saavu
Good morning
12 day streak
Ready?
Start session

Last session

28 minutes · HRV +5 · "Felt great after"

This week

3 of 4 sessions · 1h 32m total

Three steps.
That is the whole product.

SAUNA 9:41
7:12
♥ 138 BPM
1

Wear your watch in

Apple Watch goes everywhere with you. Saavu uses it to track every round of heat and cold, your heart rate the whole way through, and your HRV recovery in the minutes after. You do not touch your phone in the sauna.

2

Tap how it felt

When you step out, pick one of six faces. Tense, baseline, heat, cold, thriving, peak. Add a note if you want. That is the entire post-session UI. Thirty seconds.

9:41●●● ● ▮
How did
it feel?
Tense
Base
Heat
Cold
Thrive
Peak

HRV recovery

52 → 58 ms · +6 points · positive response
Save session
9:41●●● ● ▮
This week
Pro
Wellness score
76
Up 4 from last week

HRV trend · last 14 sessions

Climbing steadily. Recovery is improving.

An insight for you

You sleep 18 minutes longer on sauna days.
3

Watch your body change

Over weeks, your HRV trends settle. Your tolerance climbs. The face you tap shifts. Saavu shows you the pattern in a single chart, and writes you a two-sentence summary every Sunday so you know what just happened.


Built for the bench,
not the desk.

The screen you actually use during a session has to be legible with sweat on it, work upside-down, and never get in your way. Saavu's Active Session screen has been designed for exactly that.

A clear countdown

A circular timer in the colour of the phase. Ember for heat, navy for cold, ash for rest.

Live heart rate

Streamed from your watch every second. Glows ember past your comfort zone.

Round counter

Tap once to mark a round done. Long-press to add another mid-session.

Soft chimes and haptics

Gentle audio cue or a buzz on your wrist when each phase ends. Both toggleable.

9:41●●● ● ▮
Cold plunge
1:32
remaining
Round 3 of 4
Heart rate
96 BPM
Total
31:08

9:41●●● ● ▮
Rest
Inhale
Four · seven · eight
Inhale four. Hold seven. Exhale eight.
4-7-8 Box Cold Wim Hof

Five patterns.
One animated guide.

The rest phase is the most under-used part of a contrast session. Most people sit there scrolling. Saavu's breathing guide is a soft circle that scales with each inhale and exhale, so you can drop your phone face-down and just follow the rhythm.

Cold breath

Fast in, long out. Calms the gasp reflex so you can stay in longer.

Box, 4-4-4-4

Equal inhale, hold, exhale, hold. The all-rounder.

Four-seven-eight

Long exhale dominant. The one that drops you into sleep.

Wim Hof

Thirty fast cycles, then a retention. Energising primer.

Physiological sigh

Two short inhales, one long exhale. Best stress-shedder.


The app that knows
when to step out.

Sauna is mostly safe. The unsafe part is when it isn't, and you aren't sure. Saavu watches for the signs you might miss.

Heart rate ceiling alert

If your heart rate climbs past your comfort zone, both your watch and your phone buzz. You decide what to do.

Hydration nudge

Fifteen minutes after every session, a quiet notification reminds you to drink. Saavu estimates sweat loss too.

You are in control

Every alert is optional. Every notification can be muted. The app does not interrupt your session.

9:41●●● ● ▮
Sauna
2:18
Heart rate ceiling
Your heart rate has been above 175 BPM for the last 12 seconds. Consider stepping out.
I'm OK
End session

9:41●●● ● ▮
How did
it feel?
Tense
Base
Heat
Cold
Thrive
Peak
HRV recovery
+6 ms
Sweat lost
0.4 L
"Add a note..."

Thirty seconds
to remember the session.

Most fitness apps end a workout with a chart. Saavu ends it with a face. You pick one of six face-states that capture how your body actually feels. The metrics sit underneath, but the face is the headline.

Six face-states

Tense, baseline, heat, cold, thriving, peak. Each one a small animated drawing in its own colour.

HRV recovery, plain

Your HRV before and after, in one number. Positive numbers in heat are a good sign.

A place for notes

Free text. Searchable later, even across two years of sessions.

Sweat lost

A rough estimate based on duration and heat. Pairs with the hydration nudge.


Your week, told as
a single story.

Saavu Pro turns your last few weeks of sessions into something you can read. A wellness ring that fills as you build a rhythm. An HRV chart that smooths out as you adapt. A heat-tolerance progression line that climbs as you push your minutes up. And once you have ten sessions on the clock, a handful of insights written just for you.

Pro

Wellness ring

Weekly composite score from HRV, frequency, sleep correlation, and consistency. Eight weeks at a glance.

Pro

HRV trend

Last fourteen sessions plotted. See in seconds whether your nervous system is settling.

Pro

Heat tolerance

"Your sauna minutes climbed from 11 to 14 this week." Plain English, not a graph.

Pro

Personal insights

Three sentence-long insights once you have ≥10 sessions. Written just for you.

9:41●●● ● ▮
This week
Pro
Wellness score
76
↑ Up 4 from last week

HRV trend

Insight

You sleep 18 minutes longer on sauna days.

Two sentences.
Written just for you, every Sunday.

Every seven days, Saavu writes you a short personal summary based on the last week of sessions. Not a chart. Not statistics. Just two sentences, in a warm tone, that name what you have actually been doing.

9:41●●● ● ▮
Your reflection
Sunday
You pushed into longer rounds this week and your nervous system seems to be settling earlier in the heat. The thriving face appeared after every session, including the one you almost skipped on Wednesday.

Compared to last week

+1 session · +18 min total · HRV +3 average
Next reflection · 7 days

Three programmes.
One set of hands on the wheel.

If you are new to sauna or cold work, a blank timer can feel intimidating. Saavu Pro ships with three opinionated programmes, each laid out as a multi-week schedule. Tap "Start today's session" and the right durations and rounds are already loaded.

Heat tolerance
4 weeks · 12 sessions · Pro

A guided progression from eight-minute sauna rounds to eighteen-minute rounds. Three sessions per week, one rest day between each.

What you will feel: the first two weeks build a baseline. By week three you notice your breathing settle earlier. By week four, eighteen minutes feels achievable.

9:41●●● ● ▮
Heat
tolerance
Day 8 / 26
Today

10 min · 2 rounds

Volume week. Sit with the second round.
Start today's session
This week

Coming up · day 10

12 min · 2 rounds. Heat climbs.
9:41●●● ● ▮
Sleep
recovery
Day 5 / 12
Tonight

Sustained heat · 15 min

Single longer round. Stay still. About 90 min before bed.
Start session

Paired pattern

4-7-8 breathing during rest. Long exhale dominant.

Last night's sleep

7h 42m · 18 min more than your average
Sleep recovery
2 weeks · 6 sessions · Pro

An evening protocol. Warm sauna, no cold, long rest. The post-sauna drop in core temperature mimics the natural pre-sleep dip and helps you fall asleep faster.

What you will feel: two weeks is enough to notice the difference. Most users fall asleep faster by week one.


The saunas near you,
on one map.

Saavu's venue map shows every approved sauna near you, with filters for facility type. Finnish, infrared, steam room, cold plunge, wild sauna, hammam, banya, onsen.

Nearby map

Distance-sorted list, geographic map, filter by facility type. Works offline once loaded.

Check in

One tap. Auto-links the venue to your session when you save it.

Favourite a venue

Pins to the top of your home screen so you can launch your usual session from there.

9:41●●● ● ▮
Near you
7 venues
All Finnish Cold Steam
Community Sauna Baths
FINNISH · COLD · ★ 4.8
0.7 km
Banya No. 1
BANYA · STEAM · ★ 4.6
1.4 km
Beach Box Spa
WILD · COLD · ★ 4.9
3.2 km
Hotpod Sauna
FINNISH · ★ 4.5
4.0 km

9:41●●● ● ▮
Sauna
buddies
4 friends
m
@maya_h
4 sessions this week · 2h 18m
28d
k
@kai_north
3 sessions this week · 1h 45m
12d
s
@sann.a
2 sessions this week · 56m
6d
t
@tomo_w
5 sessions this week · 2h 50m
41d
+ Add a friend

Quiet social.
No feed, no likes.

Sauna is a shared ritual for a lot of people. Saavu's social layer is built around that, but without the dopamine traps of public activity feeds. There are no likes, no comments, no public photos. Just buddies, your weekly count next to theirs, and a streak you both want to keep alive.

Pick a handle

Three to thirty-two characters. Letters, numbers, underscores. Your handle is how friends find you.

Compare quietly

Friends see your weekly count, your streak, your average minutes. Never your raw sessions, notes, or HRV.

Privacy by design

Your notes, mood, and HRV stay yours. The aggregate row is the social currency.


Apple Watch.
Lock Screen. Apple Health.

Saavu does not live in just one app. It is on your wrist, on your lock screen, on your watch face, and folded into your Apple Health workout history.

9:41
Friday 17 May
Sauna · round 2 of 4
Saavu
8:24
Lock Screen Live Activity
9:41
9:41
12
DAY
HRV
58
Watch complication

Apple Watch app

Real native watch app. Start a session, see your live timer and HR, save when you are done. Works without the phone in range.

Watch face complication

Current streak and last HRV pinned to your watch face. Glance, see where you stand.

Lock Screen Live Activity

Current phase, round, and countdown on your Lock Screen and Dynamic Island. Press to expand.

Counts toward your rings

Writes to Apple Health as a workout. Minutes count toward your Move ring. Shows up alongside your runs.


Whoop. Oura.
Garmin. Polar.

Not everyone wears an Apple Watch. If you live in a Whoop, an Oura ring, or a Garmin, Saavu Pro connects to your existing wearable and pulls in recovery, sleep, and HRV data so your insights stay rich.

Pro

Whoop

Recovery, strain, sleep, cycles. Pulled in daily, shown alongside your sessions.

Pro

Oura

Daily readiness, heart rate, sleep stages. Pairs with Sleep Recovery programme.

Coming soon

Garmin

Body Battery, training readiness, HRV.

Coming soon

Polar

Recovery Pro, sleep, nightly HRV.


9:41●●● ● ▮
Your year in heat
2026
128
Sessions
62h
In heat
41d
Longest streak
38L
Sweat lost
Top venue
Community Sauna Baths
62 visits
Share your year

Saavu Wrapped.
December every year.

Every December, a small banner appears on your home screen. Tap it for your year in heat. Total sessions, total minutes, your longest streak, your favourite venue, your most-felt face state, your total sweat lost. Shareable as a single image to Instagram, iMessage, anywhere.

Twelve months of small wins, in one place, once a year.


Your sessions belong
to you.

Saavu's job is to help you understand your body, not to mine it. We never sell your data. We never share it with advertisers. The handful of friends you choose to add are the only people who see anything about you, and even then they only see aggregate counts, never individual sessions.

Export everything

One tap. A full file of every session, every check-in, every note.

Delete with grace

Thirty days to change your mind. Sign back in within the window and your account fully restores.

Encrypted on your device

Your login is locked behind your phone's passcode.

Notification opt-outs

Every notification independently togglable. Turn off what you want.

9:41●●● ● ▮
Settings
Your data

Export my data

Download a copy of everything.

Delete account

30-day grace period. Reversible.
Notifications

Session reminders

Weekly summary email


One free tier.
Two paid shapes.

Saavu's free tier is genuinely useful. You can track every session, see your last ten in history, save notes, check in at venues, write to Apple Health, build a streak. The paid tier unlocks the parts that only become valuable once you have a few weeks of data behind you.

Saavu
Free
Forever
  • Unlimited sessions on your watch
  • Last ten sessions in History
  • Face-state, HRV recovery, notes
  • Writes to Apple Health
  • Venue map and check-ins
  • Read venue reviews
  • Streak counter, one freeze per month
Saavu Pro
£39.99
Annually · save 33%
  • Everything in Pro monthly
  • Discount applied at checkout
  • Cancel any time, refund pro-rated
  • Restore purchases on any device

Billed through Apple or Google. No card details ever leave the App Store. Pro is monthly or annually, never longer. Cancel from your Apple ID settings the same way you cancel a Spotify subscription.


What we are
building after launch.

Saavu's launch is just the start. The roadmap below is what we are building over the next twelve to eighteen months, in priority order.

Soon

Late 2026

  • Venue photos for every spot on the map
  • Lock Screen Live Activity, fully live
  • Watch face complication, fully live
  • Whoop and Oura connections enabled
  • Content review by a sauna scientist
Next year

Early 2027

  • Four to six new coached programmes
  • Programmes you can build and share
  • Friend leaderboards, opt-in, group-scoped
  • Member-uploaded venue photos
  • Garmin and Polar connections
Beyond

Later 2027

  • Push notifications for streak reminders
  • Optional public activity feed
  • Verified venue accounts with a dashboard
  • Standalone Wear OS Android app
  • Body composition and period tracking

Coming soon to Apple Watch
and Wear OS.

Track your sauna sessions. See the proof. Find your next venue.