Comparison

Zero vs Experiment with Light

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

Head to head
About

Zero

This app tracks intermittent fasting and nutrition to help users achieve real body composition changes. It integrates fasting, protein intake, meals, hydration, and habits for a holistic approach to weight loss and metabolic health.

Highlights
  • Intermittent fasting timers and streaks
  • Smart meal logging with photo recognition
  • Personalized daily protein target tracking
  • Integrated fasting and protein tracking
  • Water and habit tracking
  • Science-based insights on fasting and nutrition
Features
Read full description

Zero is the all-in-one fasting tracker and nutrition app built for real results. Most fasting and weight loss apps stop at simply tracking fasts or calories. Zero connects the full picture — fasting, protein, meals, hydration, and habits — so you actually change your body composition, not just your eating schedule. Here’s how Zero helps you get there: • Track your intermittent fasting — Engage timers, streaks, and insights keep you stay motivated and consistent across your entire fasting journey. • Log meals the smart way — Skip the tedious manual meal entry routine. With Zero Plus, snap a photo and get instant macros, protein composition, and clarity on how effectively your meals support your goals. Your first meal logs are on us, so you can try it before you subscribe. • Hit your Protein Score — Zero Plus tracks a personalized daily protein target that adapts to your weight and goals. Better protein = better satiety, better muscle retention, better weight loss. Zero makes it automatic. • Complete the equation: Fasting + Protein — Most people fast or track meals. Zero brings them together so you lose weight, protect muscle, and avoid the pressure and guilt of traditional calorie trackers. • Stay hydrated to power your fasts — Water tracking with Zero Plus helps you maintain energy, reduce cravings, and support metabolic function throughout the day. • Build healthy habits that actually matter — Track movement, sleep, mood, and other daily pillars that reinforce your fasting and fueling routine. • Challenge yourself — Hit protein targets, maintain fasting streaks, and stay accountable with motivating challenges built around outcomes, not vanity metrics. • Learn the real science — Understand how fasting, protein, and hydration work together for sustainable weight loss and metabolic health — with insights from leading experts. • See measurable progress — Watch your streaks grow, your protein consistency rise, and your body composition improve with clean, insightful trend views. Whether you’re starting out or optimizing an existing routine, Zero gives you the structure, guidance, and clarity most apps miss. Zero is not a medical device and does not provide medical advice, diagnosis, or treatment. Always consult your doctor or qualified healthcare provider before making any changes to your diet, fasting routine, or health regimen. Zero is free to download, with fasting timers, streaks, weekly trends, expert articles, and challenges included. Zero Plus is an optional subscription that unlocks photo meal logging and your Protein Score, water tracking, custom fasts and saved presets, Fat-Burning Mode, the mood journal and daily habit insights, premium articles and Plus-only challenges, and monthly, yearly, and correlated charts. A free trial is available. Payment for Zero Plus will be charged to your Apple Account when you subscribe. Subscriptions automatically renew unless auto-renew is turned off at least 24 hours before the end of the current period. Manage your subscription in your Account Settings. Read more terms & conditions: Terms of use: https://www.zerolongevity.com/terms-of-use Privacy policy: https://www.zerolongevity.com/privacy-policy

About

Experiment with Light

Access Quaker "Experiment with Light" meditation recordings and scripts. Choose from four versions with male or female voice options, or read the full script. This app works offline once installed.

Highlights
  • Meditation recordings
  • Full scripts
  • Multiple versions
  • Male/female voice options
  • Offline functionality
Features
Read full description

Recordings and scripts for all versions of the Quaker Experiment with Light. Four different versions with a choice of male or female voice recording as well as the full script for those who prefer reading it. Once installed, the app doesn’t require any internet access and works offline.

Screenshots

Zero4 screens
Experiment with Light4 screens

Verdict

The call

Zero and Experiment with Light both sit at 4.8 stars, but that hides the real split: 100% of Experiment with Light's written reviews are positive against 32% of Zero's. Experiment with Light also leads on in-app purchases (none vs 17) and iOS requirement (9.0 vs 17.0). Zero's advantage is ratings volume (445K vs 4) and chart position (#109 vs unranked). On price, rating, update cadence and ads 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 sells 10 in-app purchases, starting at $9.99 per month. Experiment with Light 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 Zero against 4.8 for Experiment with Light. That said, the two scores are not equally well evidenced: Zero has 445K ratings behind it against 4, so its average is the more settled of the two. Written reviews are what separate them: 32% of Zero's written reviews are positive against 100% of Experiment with Light's.

UpkeepUpdate frequency

Zero ships an update every 2 weeks, Experiment with Light every 3 weeks. The most recent releases landed on October 27, 2026 and October 24, 2026 respectively.

Scorecard6 real differences · 5 level
Zero versus Experiment with Light: the parameters behind the verdict, then further details
ParameterZeroExperiment with Light
PriceFreeFree
Rating4.8 (445K ratings) — better4.8 (4 ratings)
Positive reviews32.2% of reviews100.0% of reviews — better
Number of ratings445K — better4
Update frequencyEvery 2 weeks — betterEvery 3 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemiumFree — better
Best chart rank#109 — better—
DevicesiPhone, Apple WatchiPhone, iPad, iPod — better
Requires iOS17.09.0 — better
Further details — not scored
Size195 MB267 MB
Age rating17+4+
DeveloperZero Longevity Science, Inc.Alain Foussat

Customer experience

Zero

All ratings445,285 ratings
Positive96.3%
Neutral2.1%
Negative1.6%
Written reviews1,393 reviews
Positive32.2%
Neutral8.5%
Negative59.3%

Experiment with Light

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

Bugs and requests

Zero

Reported bugs

3 issues
  • Password reset problems
  • Inaccurate fasting time tracking
  • Inability to exit trial without subscribing

Requested features

6 requests
  • Custom fasting periods longer than 24 hours
  • Ability to edit fasting type and duration
  • Integration with more health/fitness apps
  • Water intake tracking
  • Personalized fasting recommendations
Show 1 more
  • Improved data visualization and analytics

Experiment with Light

Not enough reviews yet to summarise bugs or requests.

In-app purchases

10 purchases

Zero

Subscriptions10
  • Zero Plus Subscription2 variants$9.991 Month
  • Zero Plus Subscription7 Days trial$9.991 Month
  • Zero Plus Subscription$39.991 Year
Show 7 more
  • Zero Plus Subscription7 Days trial$49.991 Year
  • Zero Plus Subscription7 Days trial3 variants$69.991 Year
  • Zero Plus Subscription$69.991 Year
  • Zero Plus Subscription1 Year trial3 variants$69.991 Year
  • Zero Plus Subscription1 Month trial$69.991 Year
  • Zero Plus Subscription1 Month trial$89.991 Year
  • Zero Plus Subscription7 Days trial$89.991 Year
None

Experiment with Light

No in-app purchases

Questions

Is Zero free?
Zero is free to download, with in-app purchases available.
Is Experiment with Light free?
Experiment with Light is free to download, with no in-app purchases.
Which has better reviews, Zero or Experiment with Light?
Zero is rated higher. Zero averages 4.8 out of 5 from 445K ratings, while Experiment with Light averages 4.8 from 4 ratings.
Do Zero or Experiment with Light have ads?
Neither Zero nor Experiment with Light shows ads.
Which is updated more often, Zero or Experiment with Light?
Zero ships an update every 2 weeks, and Experiment with Light every 3 weeks. Most recently, Zero was updated on October 27, 2026 and Experiment with Light on October 24, 2026.

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