Comparison

Netzero for Powerwall vs CalaWater

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

Head to head
About

Netzero for Powerwall

Automate your home energy system to maximize savings and monitor your Powerwall's health. Integrate with utility providers for dynamic pricing and receive alerts for solar or battery issues. Gain insights into energy production and use your device as a home energy dashboard.

Highlights
  • Powerwall automation and scheduling
  • Utility tariff integration
  • Solar production monitoring
  • Powerwall health alerts
  • Home energy dashboard
  • Advanced diagnostics
Features
Read full description

Increase savings with Powerwall automation and utility integrations. Connect your energy devices, monitor Powerwall health, and detect solar issues early. Advanced features require a subscription after a 30-day free trial. - Take charge of your Powerwall. Schedule charging, discharging, and backup settings. Export stored energy to the grid when export prices are highest, or before a period of cheap or free electricity. Prevent unnecessary discharge during EV charging and improve efficiency. Automate your home energy with device integrations. - Connect your EV charger, EV, and heating/cooling devices. Pre-heat or pre-cool your home when electricity is cheap, or pause EV charging and heating/cooling during outages. Supports 500+ devices across 50+ brands. - Octopus Energy users benefit from automatic Powerwall charging during Intelligent Octopus Go sessions. Supports Agile Octopus, Tibber, Amber Electric, ComEd Hourly Pricing, and Ameren Power Smart Pricing. Netzero configures Powerwall with live pricing to help cut your bills. - Receive automatic alerts for solar or battery issues. Track Powerwall capacity and degradation to stay within warranty limits. - Get daily, monthly, and yearly production estimates. Spot solar performance issues early. Use the app on your tablet or phone as an always-on home energy dashboard. - Download detailed data, view string-level solar performance, access weather data and developer tools, and enjoy ongoing feature updates. Apple Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

CalaWater

Monitor and control your intelligent heat pump water heater remotely. Track usage, optimize heating schedules for solar production or vacation, and ensure hot water availability. Receive ongoing system updates for improved performance.

Highlights
  • Track hot water usage patterns
  • Sync heating with solar production
  • View energy usage
  • Boost production on demand
  • Schedule vacation energy savings
  • Monitor real-time availability and performance
  • Configure system run times
Features
Read full description

The Cala app is the companion to your Cala intelligent heat pump water heater. It allows you to monitor and control key aspects of your system to ensure it performs according to your household’s needs and preferences. With the app, you can: - Track your home’s hot water usage patterns - Sync your water heater to automatically heat during solar production - View your water heater’s energy usage - Boost production when family or guests are in town - Schedule your vacation for energy savings - Monitor hot water availability and performance in real-time - Configure when the system runs to avoid noise or cool air during specific times The Cala app also enables ongoing system updates and performance improvements delivered over time. An internet connection is required to access the features in the Cala mobile app. While your Cala water heater will function without the app, features like remote control and energy optimizations are only available when the app is connected to the internet No subscription is required. The Cala app is free to use.

Screenshots

Netzero for Powerwall4 screens
CalaWater4 screens

Verdict

The call

The clearest difference is in-app purchases: CalaWater at none against Netzero for Powerwall's 2. CalaWater also leads on review sentiment (100% vs 90%). Netzero for Powerwall's advantage is ratings volume (801 vs 6) and update cadence (weekly vs every 2 weeks). On price, rating, 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. Netzero for Powerwall sells 2 in-app purchases, starting at $6.99 per month. CalaWater asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for Netzero for Powerwall against 4.8 for CalaWater. That said, the two scores are not equally well evidenced: Netzero for Powerwall has 801 ratings behind it against 6, so its average is the more settled of the two. Written reviews are what separate them: 90% of Netzero for Powerwall's written reviews are positive against 100% of CalaWater's.

UpkeepUpdate frequency

Netzero for Powerwall ships an update weekly, CalaWater every 2 weeks. The most recent releases landed on October 27, 2026 and October 24, 2026 respectively.

Scorecard5 real differences · 5 level
Netzero for Powerwall versus CalaWater: the parameters behind the verdict, then further details
ParameterNetzero for PowerwallCalaWater
PriceFreeFree
Rating4.8 (801 ratings)4.8 (6 ratings) — better
Positive reviews90.5% of reviews100.0% of reviews — better
Number of ratings801 — better6
Update frequencyWeekly — betterEvery 2 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemiumFree — better
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.415.1 — better
Further details — not scored
Size61 MB59 MB
Age rating4+4+
DeveloperNetzero Labs, IncCala Systems, Inc.

Customer experience

Netzero for Powerwall

All ratings799 ratings
Positive95.0%
Neutral1.6%
Negative3.4%
Written reviews566 reviews
Positive90.5%
Neutral2.8%
Negative6.7%

CalaWater

All ratings6 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Netzero for Powerwall

Reported bugs

2 issues
  • May not be compatible with PW3
  • Diagnostic screen stays black

Requested features

2 requests
  • stop battery charging?
  • AND function on the conditionality

CalaWater

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

Netzero for Powerwall

Subscriptions2
  • Netzero Pro - Monthly$6.991 Month
  • Netzero Pro - Annual$69.991 Year
None

CalaWater

No in-app purchases

Questions

Is Netzero for Powerwall free?
Netzero for Powerwall is free to download, with in-app purchases available.
Is CalaWater free?
CalaWater is free to download, with no in-app purchases.
Which has better reviews, Netzero for Powerwall or CalaWater?
CalaWater is rated higher. Netzero for Powerwall averages 4.8 out of 5 from 801 ratings, while CalaWater averages 4.8 from 6 ratings.
Do Netzero for Powerwall or CalaWater have ads?
Neither Netzero for Powerwall nor CalaWater shows ads.
Which is updated more often, Netzero for Powerwall or CalaWater?
Netzero for Powerwall ships an update weekly, and CalaWater every 2 weeks. Most recently, Netzero for Powerwall was updated on October 27, 2026 and CalaWater on October 24, 2026.

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