Comparison

HeatWave vs Coolhouse

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

Head to head
About

HeatWave

This app monitors outdoor and indoor temperatures to alert you when to open or close your windows for optimal home climate control. It uses your HomePod's sensor and local weather forecasts to provide timely notifications, helping you save energy and stay comfortable without an air conditioner.

Highlights
  • Real-time indoor/outdoor temperature display
  • Forecast-based opening/closing alerts
  • 30-minute advance notifications
  • Home screen widgets
  • Privacy-first, no servers or tracking
  • Multi-language support
Features
Read full description

A heat wave's worst trick is making you feel powerless. HeatWave is the simple, beautiful way to take back control of your home's temperature — without an air conditioner. Most of us already know the trick: open the windows when it's cooler outside, shut them when it gets hotter. The problem is knowing exactly when. HeatWave watches the weather forecast for your location and your indoor temperature, then quietly pings you 30 minutes before the air outside is about to cross the air inside. Open up just before it gets cool. Shut up just before it gets warm. That's it. HOW IT WORKS HeatWave uses Apple Weather to fetch a fresh, accurate forecast for your exact location. It uses your HomePod's built-in temperature sensor via Apple's Shortcuts app to know how warm it is inside. A guided setup wizard walks you through everything in under five minutes — tap the shortcut once, point it at your HomePod, then schedule when it runs. The more often the shortcut runs, the more precise your alerts become. HeatWave suggests a sensible minimum (hourly between 7–10am and 6–9pm) and tells you how to fine-tune it further. ON THE DASHBOARD A single screen tells you everything you need to know: • A bold status card that says "Open the windows" or "Shut the windows" right now. • Side-by-side cards showing your live indoor and outdoor temperatures, with timestamps so you always know how fresh the data is. • A countdown to the next change — "Open in 1h 24m" — with the forecast temperature at that moment. • A 12-hour bar chart of upcoming outdoor temperatures so you can plan your day at a glance. WIDGETS FOR YOUR HOME SCREEN Add HeatWave to your home or lock screen and you may never need to open the app. Small, medium, and large widgets show the current recommendation, your inside/outside temperatures, and a live countdown to the next window change. Lock-screen accessory widgets (circular, rectangular, inline) keep an eye on things at a glance. NOTIFICATIONS THAT FIRE 30 MINUTES AHEAD Get a gentle ping half an hour before each crossover, with the projected outdoor temperature so you can decide if it's worth getting up for. A built-in buffer prevents flip-flop alerts when temperatures wobble. WHY HEATWAVE • No air conditioner needed — works with the windows you already have. • Saves electricity and protects you from heat exhaustion in countries unprepared for high temperatures. • Beautiful, friendly UI with subtle haptics and warm gradients. • Privacy-first: everything lives on your device. No accounts, no servers, no tracking. • Fully localised in six languages. REQUIREMENTS • HomePod mini or HomePod 2nd generation (for indoor temperature) • iPhone running iOS 17 or later • Apple Weather (WeatherKit) for outdoor forecasts A heat wave doesn't have to leave you sweating. With HeatWave, your home gets a head start every time the air outside changes. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Coolhouse

Features
Read full description

Coolhouse — should you open the windows? During hot weather, the right move isn't always obvious: opening at the wrong time heats your home up. Coolhouse tells you whether to open or close your windows right now — and when — to keep the inside cool, without air conditioning. The app compares your city's outdoor temperature with your indoor temperature in real time, and applies rules drawn from scientific studies. Nothing is made up. What Coolhouse does: • A clear verdict at a glance: OPEN, CLOSE or airing possible • The right window to ventilate, hour by hour • Tropical night warning (overnight low ≥ 20 °C / 68 °F) • Estimated indoor temperature, adjustable to how it actually feels • Next action to plan ahead (“remember to close before noon”) • Automatic location or manual city search — your last place is remembered Science-based advice: Every rule is sourced and viewable in the app — including the WHO and building thermal-comfort standards (EN 16798-1, ASHRAE 55, CIBSE). Your privacy: No account, no ads. Your location is used only to fetch local weather and is never shared. — Thermal-comfort guidance, not medical advice. In an emergency, call your local emergency number.

Screenshots

HeatWave3 screens
Coolhouse4 screens

Verdict

The call

The clearest difference is in-app purchases: Coolhouse at none against HeatWave's 3. Coolhouse also leads on iOS requirement (15.1 vs 17.6). On price, update cadence, ads and device support 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. HeatWave sells 3 one-off in-app purchases. Coolhouse asks for nothing beyond the download.

UpkeepUpdate frequency

HeatWave ships an update every 11 days, Coolhouse weekly. The most recent releases landed on August 14, 2026 and September 9, 2026 respectively.

Scorecard2 real differences · 6 level
HeatWave versus Coolhouse: the parameters behind the verdict, then further details
ParameterHeatWaveCoolhouse
PriceFreeFree
Positive reviews100.0% of reviews—
Update frequencyEvery 11 daysWeekly — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree—
DevicesiPhone, iPadiPhone, iPod
Requires iOS17.615.1 — better
Further details — not scored
Size29 MB43 MB
Age rating4+4+
DeveloperChristopher HeffermanArnaud Allouis

In-app purchases

3 purchases

HeatWave

One-time3
  • Coffee Money Tip$2.99
  • Pint Money Tip$4.99
  • Dinner Money Tip$14.99
None

Coolhouse

No in-app purchases

Questions

Is HeatWave free?
HeatWave is free to download, with in-app purchases available.
Is Coolhouse free?
Coolhouse is free to download, with no in-app purchases.
Do HeatWave or Coolhouse have ads?
Neither HeatWave nor Coolhouse shows ads.
Which is updated more often, HeatWave or Coolhouse?
HeatWave ships an update every 11 days, and Coolhouse weekly. Most recently, HeatWave was updated on August 14, 2026 and Coolhouse on September 9, 2026.

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