Comparison

JouleBug vs Zero CO2

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

Head to head
About

JouleBug

This app is designed to enhance workplace experiences by fostering environmental and social stewardship through collective action. It offers tailored sustainability programs, tracks impact metrics, and encourages employee engagement through challenges and social interactions.

Highlights
  • Employee Engagement Hub
  • Tailored Sustainability Programs
  • Metrics for Impactful Insights
  • Inspirational Challenges
  • Dynamic Social Interactions
Features
Read full description

Say farewell to JouleBug: Legacy. Embrace the new JouleBug, Employee Engagement Hub, for better workplace experiences! We're thrilled to introduce the next evolution of JouleBug – the ultimate hub for fostering better workplace experiences while championing environmental and social stewardship through collective action. Key Features: * Employee Engagement Hub: Empower your workforce to connect, collaborate, and thrive in a supportive environment that promotes well-being through collective action. * Tailored Sustainability Programs: Cultivate a culture of environmental and social stewardship with personalized programs that align with your organization's values and goals. * Metrics for Impactful Insights: Track and measure your organization's sustainability impact in real-time, gaining valuable insights into areas for improvement and celebrating collective achievements. * Inspirational Challenges: Spark enthusiasm and foster camaraderie among employees with engaging challenges crafted to inspire action and drive positive change. * Dynamic Social Interactions: Cultivate a sense of belonging and community through real-time updates, interactive discussions, and shared experiences on your sustainability journey. Download the all-new JouleBug app at https://joulebug.com/download today and enter access code "JouleBuggies" to join JouleBug Nation, where you'll experience a transformative journey of well-being and sustainability. Together, let's foster a culture that not only benefits people but also makes a positive impact on the world around us. Sincerely, The JouleBug Team

About

Zero CO2

This app tracks your phone's carbon footprint from data usage and helps you offset emissions by planting trees. Monitor your CO2 output and see how your reforestation efforts compensate for it, receiving certificates for each planted tree.

Highlights
  • Monitors phone carbon footprint
  • Tracks CO2 emissions from data usage
  • Compensates emissions by planting trees
  • Visualizes CO2 emissions and tree compensation
  • Provides certificates for planted trees
Features
Read full description

ZeroCO2 monitors your phone's carbon footprint and keeps track of the CO2 emissions from your device. These CO2 emissions come from the data usage of your device. All cloud-services, emails, search queries, social network activities etc, are facilitated by large Data Centers, which consume large amounts of electricity to keep your data streams flowing. Over its lifetime, an iPhone can emit up to 60 kilograms of CO2. This electricity typically does not come 100% from green sources, and therefore leads to CO2 emissions. That's equivalent to more than 300 kilometers driving in a petrol-fueled car. Do you want your phone to become CO2-neutral? Then use the app to plant trees to compensate your emissions! With its comprehensive graphs, you can easily monitor how much CO2 you emit, and how your planted trees compensate these emissions. With every planted tree, you receive a certificate that proves the authenticity and shows the location of the planted tree. Prevent climate change, and become a carbon-neutral iPhone user! Note: Trees are planted by our partner Tree-Nation, the worldwide platform to reforest the world and fight climate change. All trees planted by Tree-Nation are certified by the best in class and most renowned certification standards that exist in this field. For this, Tree-Nation works with third-party certification organizations such as VCS, Gold Standard, and Plan Vivo.

Screenshots

JouleBug4 screens
Zero CO24 screens

Verdict

The call

The clearest difference is rating: Zero CO2 at 5.0 against JouleBug's 4.4. Zero CO2 also leads on review sentiment (100% vs 70%) and update cadence (every 3 days vs every 3 months). JouleBug's advantage is in-app purchases (none vs 1) and ads (none vs shown). On price 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. Zero CO2 sells 1 one-off in-app purchase. JouleBug asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Zero CO2 holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: JouleBug has 41 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 70% of JouleBug's written reviews are positive against 100% of Zero CO2's.

UpkeepUpdate frequency

JouleBug ships an update every 3 months, Zero CO2 every 3 days. The most recent releases landed on November 6, 2026 and November 3, 2026 respectively.

Scorecard8 real differences · 2 level
JouleBug versus Zero CO2: the parameters behind the verdict, then further details
ParameterJouleBugZero CO2
PriceFreeFree
Rating4.4 (41 ratings)5.0 (4 ratings) — better
Positive reviews70.0% of reviews100.0% of reviews — better
Number of ratings41 — better4
Update frequencyEvery 3 monthsEvery 3 days — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPodiPhone, iPod
Requires iOS13.0 — better15.5
Further details — not scored
Size70 MB40 MB
Age rating12+12+
DeveloperCleanbit Systems, Inc.Caramba App Development

Customer experience

JouleBug

All ratings41 ratings
Positive82.9%
Neutral4.9%
Negative12.2%
Written reviews50 reviews
Positive70.0%
Neutral10.0%
Negative20.0%

Zero CO2

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

JouleBug

Reported bugs

8 issues
  • App closes when buzzing
  • Server error prevents usage
  • App won't load after initial setup
  • Login errors, requires Facebook
  • Accidental buzzes cannot be deleted
Show 3 more
  • Glitchy titles
  • Incomplete button text and options
  • Crash on download

Requested features

15 requests
  • Add more sustainable actions/challenges
  • Update book and movie options
  • Add a clothing section with sustainable options
  • Allow deletion of unintentional buzzes
  • Favorite/categorize activities
Show 10 more
  • Track negative impact
  • Educate on conscious consumerism and waste cycle
  • Add Apple Watch capability
  • Allow users to submit new sustainability actions
  • Make seasonal actions location-specific
  • Add more social login options
  • Translate to other languages (e.g., Turkish)
  • Add a 'To-Do List' or 'Goals' section
  • More badges
  • More pins

Zero CO2

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

JouleBug

No in-app purchases

1 purchases

Zero CO2

One-time1
  • Plant your tree$0.99

Questions

Is JouleBug free?
JouleBug is free to download, with no in-app purchases.
Is Zero CO2 free?
Zero CO2 is free to download, with in-app purchases available.
Which has better reviews, JouleBug or Zero CO2?
Zero CO2 is rated higher. JouleBug averages 4.4 out of 5 from 41 ratings, while Zero CO2 averages 5.0 from 4 ratings.
Do JouleBug or Zero CO2 have ads?
Zero CO2 shows ads; JouleBug does not.
Which is updated more often, JouleBug or Zero CO2?
JouleBug ships an update every 3 months, and Zero CO2 every 3 days. Most recently, JouleBug was updated on November 6, 2026 and Zero CO2 on November 3, 2026.

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