Comparison

ReViiV vs NBack

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

Head to head
About

ReViiV

This app offers customized daily breathing exercises designed to alleviate post-viral symptoms like fatigue, brain fog, and loss of taste/smell. It utilizes scientifically backed techniques across 16 progressive stages to promote steady improvement and symptom relief.

Highlights
  • Customized daily breathing exercises
  • 16 progressive stages for improvement
  • Relief from fatigue, brain fog, taste/smell loss
  • 8 scientifically backed techniques
  • Weekly progress assessments and graphs
  • Detailed guides and technique resources
Features
Read full description

** Rapid Long-Haul Relief ** Experience fast relief from your Long-Haul / Post-Viral symptoms with ReViiV, a breakthrough app offering customized daily exercises designed to treat common Long-Haul symptoms. Imagine less fatigue, clearer thinking, and the return of taste/smell, often starting within 24 hours – all possible through our custom breathing program. Featuring 8 scientifically backed techniques fused into simple, daily exercises, this is more than deep breaths; it's about continuous improvement and reclaiming your health. (View the Full Medical Paper: https://tinyurl.com/mukdb2cc) ** Steady Improvement over 16 Stages ** ReViiV is designed to quickly relieve many common Long-Haul (PASC) symptoms, including Fatigue, Taste/Smell loss, Breathlessness, “Brain Fog’, Muscle/Joint pain, Insomnia, and more. ReViiV uses 5-minute daily breathing exercises, progressively tailored to your needs, to both relieve symptoms and facilitate steady, incremental improvement over 16 stages. Weekly assessments and graphs show your progress along with visual aids, detailed guides, and resources to ensure proper technique. ** Featuring 8 Scientifically Backed Techniques ** Drawing from the latest Long-Haul (PASC) research, as well as respiratory and cognitive-behavioral therapy, ReViiV's effectiveness stems from 8 scientifically backed techniques fused into a highly effective breathing program: 1. Nasal Breathing: ReViiV promotes nasal breathing 24/7 to increase the efficiency of your lungs, improve oxygen intake, reduce fatigue, and help restore taste & smell. 2. Prolonged Exhalation: By emphasizing long exhales, ReViiV aims to reduce breathlessness, relax your body, improve your sleep, and improve lung function. 3. Diaphragm Activation: ReViiV encourages deep 'belly breathing' to improve your lung function, reduce fatigue and shortness of breath. By stimulating the nervous system, it also reduces stress and anxiety, enhancing well-being. 4. Oxygen/CO2 Regulation: ReViiV aims to improve your lung capacity and balance the levels of oxygen and CO2 in your body by fostering the Bohr Effect, helping to alleviate symptoms like fatigue, breathlessness, and ‘brain fog’. 5. Regulated Immune System: ReViiV's breathing exercises are designed to keep your immune system in check, reducing inflammation and other immune-related symptoms often seen in Long-Haulers. 6. Olfactory Re-training: ReViiV incorporates specific exercises that can enhance your sensitivity to smell and taste, especially useful for Long-Haulers. 7. Breath-Holding: When you're ready, ReViiV introduces daily breath-holding exercises to help your body adapt to higher CO2 levels, improving overall body efficiency. 8. Stress Reduction and Mindfulness: ReViiV includes mindfulness techniques to help reduce fatigue, improve sleep, and combat stress, anxiety, and depression. ** Key Features & Functionality ** • Safe, 100% natural Long-Haul breathing therapy, requiring just minutes a day. • Harness 8 potent techniques for rapid Long-Haul symptom relief and ongoing improvement. • Benefits often noticeable within 24 hours. • Weekly assessments and graphs to measure and track your progress. • Progressive 16-stage guided program with three intensity levels. • Auto-adjusts exercise intensity based on your progress. • Co-created by a Long-Hauler along with leading post-viral research and trials. • Multiple breath counters and countdown timers within a user-friendly interface. • Access to additional Long-Haul resources, guides and tips to ensure you're on the right track. • Daily exercises tailored for morning focus, afternoon energy, and evening relaxation. Download ReViiV FREE Now! ** For More Information ** - How ReViiV Works: https://reviiv.me/howitworks - Full Medical Paper: https://tinyurl.com/mukdb2cc Terms of use: https://www.Apple.com/legal/internet-services/itunes/dev/stdeula/

About

NBack

This scientifically validated cognitive training app is designed to enhance focus, memory, and problem-solving skills. It utilizes the dual n-back method, proven to increase fluid intelligence, offering a challenging yet rewarding experience for those seeking mental improvement.

Highlights
  • Scientifically validated cognitive training
  • Dual n-back method for fluid intelligence
  • Boosts memory and focus
  • Enhances problem-solving skills
  • Progress tracking with data-backed gains
  • Customizable user experience
Features
Read full description

The N-Back Challenge isn’t just a game.
 It’s a scientifically validated cognitive upgrade —
 engineered to boost your IQ in just 7 hours total. Built on Research. Designed for Results.
 Forget brain-training fluff.
 This is dual n-back — the only method proven to actually increase fluid intelligence, with results published in New York Times, The Wall Street Journal and other top journals. But here’s the truth:
 It’s brutal. It’s exhausting. It works. If you can complete 20 sessions, you may unlock:
 • Sharper memory
 • Faster learning
 • Enhanced problem-solving
 • Stronger focus under pressure Track your progress.
 See real gains — backed by data.
 All within a beautifully designed, customizable experience. This is not for everyone.
 But if you’re hungry to evolve,
The Challenge awaits. This app is only available in English. Privacy Policy: https://boostiq.app/privacypolicy.html Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

ReViiV4 screens
NBack4 screens

Verdict

The call

The clearest difference is rating: NBack at 5.0 against ReViiV's 4.5. NBack also leads on review sentiment (100% vs 75%). ReViiV's advantage is update cadence (monthly vs every 2 months) and ratings volume (8 vs 1). On price, ads, in-app purchases and monetization model 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. ReViiV sells 2 in-app purchases, starting at $0.99 per month and NBack sells 2 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

NBack holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: ReViiV has 8 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 75% of ReViiV's written reviews are positive against 100% of NBack's.

UpkeepUpdate frequency

ReViiV ships an update monthly, NBack every 2 months. The most recent releases landed on October 24, 2026 and October 11, 2026 respectively.

Scorecard5 real differences · 5 level
ReViiV versus NBack: the parameters behind the verdict, then further details
ParameterReViiVNBack
PriceFreeFree
Rating4.5 (8 ratings)5.0 (1 ratings) — better
Positive reviews75.0% of reviews100.0% of reviews — better
Number of ratings8 — better1
Update frequencyMonthly — betterEvery 2 months
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFreemium
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.0 — better15.1
Further details — not scored
Size25 MB44 MB
Age rating12+4+
DeveloperMartysoft LLCeric cesar

Customer experience

ReViiV

All ratings8 ratings
Positive87.5%
Neutral0.0%
Negative12.5%
Written reviews4 reviews
Positive75.0%
Neutral0.0%
Negative25.0%

NBack

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

2 purchases

ReViiV

Subscriptions2
  • Long Haul Breathing Therapy3 Days trial$0.991 Month
  • Long Haul Breathing Therapy3 Days trial$6.991 Year
2 purchases

NBack

Subscriptions2
  • Monthly membership$1.991 Month
  • Yearly membership$14.991 Year

Questions

Is ReViiV free?
ReViiV is free to download, with in-app purchases available.
Is NBack free?
NBack is free to download, with in-app purchases available.
Which has better reviews, ReViiV or NBack?
NBack is rated higher. ReViiV averages 4.5 out of 5 from 8 ratings, while NBack averages 5.0 from 1 ratings.
Do ReViiV or NBack have ads?
Neither ReViiV nor NBack shows ads.
Which is updated more often, ReViiV or NBack?
ReViiV ships an update monthly, and NBack every 2 months. Most recently, ReViiV was updated on October 24, 2026 and NBack on October 11, 2026.

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