Comparison

KAI by Keep Labs vs Variable Resistance Training

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

Head to head
About

KAI by Keep Labs

An AI-powered coach designed to help individuals with rare conditions manage their treatment and symptoms. It offers tools for tracking, understanding health patterns, and staying on track with therapy, providing support for both patients and caregivers.

Highlights
  • AI-powered treatment coaching
  • Symptom tracking and pattern analysis
  • Smart medication reminders
  • Health insights and pattern discovery
  • Support for patients and caregivers
  • Treatment and symptom management tools
Read full description

MEET KAI, YOUR PERSONAL HEALTH ALLY. Kai is an AI health companion for people living with rare conditions, and the people who care for them. Talk to Kai the way you'd talk to someone who knows your story. Kai listens, remembers, and helps you keep a record of what living with your condition is really like – the part that usually gets lost between doctor visits. PICK UP WHERE YOU LEFT OFF The prompts waiting for you when you open Kai aren't generic. They're drawn from your past conversations: a thread you left half-finished, something you mentioned in passing, a pattern worth coming back to. Tap one and you're straight back into it, with no need to explain yourself again. Or just tell Kai what's on your mind. A WEEKLY REFLECTION Most weeks, Kai brings you one thing it wants to understand properly – what a harder week looked like, how a treatment decision felt, who you lean on. It's a conversation, not a form. A few minutes, in your own words. When you're done, Kai writes up what you shared and saves it for you, with points as a small thank-you. YOUR HEALTH JOURNAL For You is your health in your own words: how your symptoms have actually been, and the reflections you've shared. It builds itself as you talk, so there's nothing to log and nothing to keep up with. SHARE YOUR STORY WITH YOUR DOCTOR Before an appointment, create a summary of your health journey so your doctor sees the full picture, not just what you remember in the room. It's yours to take with you whenever you need it. EVERY CONVERSATION, SAVED Everything you've talked about is saved and titled, so you can go back and re-read a conversation instead of trying to remember it. Your past chats, reflections, summaries, symptoms and settings all sit together in one menu. FOR PATIENTS AND CAREGIVERS Whether you're living with a rare condition or caring for someone who is, Kai is someone to turn to with questions, for reassurance, or just to talk through a hard day. DESIGNED WITH CARE We created Kai because living with a rare condition places a real burden on patients and caregivers between doctor visits. Our purpose is simple: to ease that load, so you can focus on living your life as fully as possible. NOTE: Kai does not provide medical advice or diagnosis.

About

Variable Resistance Training

This app offers advanced tracking for resistance band workouts, automatically calculating resistance and progression based on your saved equipment. It also supports tracking weights and calisthenics, providing detailed analytics and a video library for exercise demonstrations.

Highlights
  • Automatic band resistance calculation
  • Dynamic resistance progression generation
  • Weight and calisthenics tracking
  • Full video exercise library
  • Detailed analytics and progress charts
  • Customizable rest timer
  • Superset functionality
Features
Read full description

The most advanced resistance band training app is here. Track bands, weights, calisthenics, and sliding bench trainers - all in one app with an intuitive, user-friendly interface. Automatically calculate band resistance and generate a resistance progression based on your saved equipment. Train smarter, see real progress, and stay consistent every session. Unlike generic fitness apps, Variable Resistance Training is the only app that combines true VRT tracking with weights, calisthenics, and sliding bench trainers, making it a complete solution for all strength and bodyweight training. Revolutionary Automatic Band Progression: - Add your bands (or any combination) to your Saved Equipment List - The app automatically generates a dynamic progression list from lowest to highest resistance, showing exact band or stacked band combinations for each resistance level - Band prestretch values are automatically calculated based on your equipment dimensions, giving you an additional difficulty indicator - Tap + / - during your workout and the app instantly updates resistance and selects the correct band or stacked combination, removing all guesswork - Works with any bands - Flexible, intuitive design makes adding/removing exercises, sets, and progression adjustments effortless Track Weights, Calisthenics, & Sliding Bench Trainers: - Standard bodyweight exercises (no equipment needed) - Assisted calisthenics using bands for support - Weighted exercises alongside your VRT workouts - Sliding bench trainers including level and added resistance Other Key Features: - Band Video Library – Clear demonstrations for VRT exercises - Robust Equipment Library – Pre-loaded with data from leading band systems, fully compatible with any resistance band or product - Custom Exercises & Programs – Build your own routines or adapt existing ones easily - Advanced Logging – Track sets, reps, RPE, resistance levels, and workout history - Customizable Rest Timer – Set and adjust rest periods for each exercise or set, with flexible options to match your workout pace - Detailed Analytics – See progress charts and track performance over time - Supports All Training Styles – Resistance bands, weights, calisthenics, and sliding bench trainers - Smarter Progression – Measure your true training load, remove guesswork, and make consistent gains - Superset Functionality – Link exercises and autoatically switch between them for seemless set tracking - Extremely User-Friendly UI – Effortlessly navigate workouts, progressions, exercises, and sets with flexible controls Why choose Variable Resistance Training? - Only app with true prestretch-based resistance tracking - Only app with automatic band progression from saved equipment - Only app that tracks bands, weights, calisthenics, and sliding bench trainers - Only app that combines powerful features with an extremely user-friendly, flexible interface for effortless tracking Whether your goal is building muscle, improving mobility, or training at home, Variable Resistance Training gives you the most versatile, accurate, and complete strength tracking system available for training with various modalities. Note: A subscription is required to continue using Variable Resistance Training after your 1-month free trial. Terms of Service: https://vrt-app.com/terms-of-service/ Privacy Policy: https://vrt-app.com/privacy-policy/ https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

KAI by Keep Labs4 screens
Variable Resistance Training4 screens

Verdict

The call

The clearest difference is rating: KAI by Keep Labs at 5.0 against Variable Resistance Training's 4.0. KAI by Keep Labs also leads on in-app purchases (none vs 3) and ads (none vs shown). Variable Resistance Training's advantage is update cadence (every 6 days vs every 3 weeks). On price, ratings volume, device support and iOS requirement 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. Variable Resistance Training sells 3 in-app purchases, starting at $3.99 per month. KAI by Keep Labs asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

KAI by Keep Labs holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 2 and 4 respectively.

UpkeepUpdate frequency

KAI by Keep Labs ships an update every 3 weeks, Variable Resistance Training every 6 days. The most recent releases landed on October 9, 2026 and October 10, 2026 respectively.

Scorecard5 real differences · 4 level
KAI by Keep Labs versus Variable Resistance Training: the parameters behind the verdict, then further details
ParameterKAI by Keep LabsVariable Resistance Training
PriceFreeFree
Rating5.0 (2 ratings) — better4.0 (4 ratings)
Number of ratings24 — better
Update frequencyEvery 3 weeksEvery 6 days — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS15.115.0 — better
Further details — not scored
Size56 MB97 MB
Age rating12+4+
DeveloperKEEP Labs Inc.Andrew Soumbos

Customer experience

KAI by Keep Labs

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Variable Resistance Training

All ratings4 ratings
Positive75.0%
Neutral0.0%
Negative25.0%

In-app purchases

None

KAI by Keep Labs

No in-app purchases

3 purchases

Variable Resistance Training

Subscriptions2
  • VRT Monthly1 Month trial$3.991 Month
  • VRT Annual1 Month trial$39.991 Year
One-time1
  • VRT Lifetime Pro$149.99

Questions

Is KAI by Keep Labs free?
KAI by Keep Labs is free to download, with no in-app purchases.
Is Variable Resistance Training free?
Variable Resistance Training is free to download, with in-app purchases available.
Which has better reviews, KAI by Keep Labs or Variable Resistance Training?
KAI by Keep Labs is rated higher. KAI by Keep Labs averages 5.0 out of 5 from 2 ratings, while Variable Resistance Training averages 4.0 from 4 ratings.
Do KAI by Keep Labs or Variable Resistance Training have ads?
Variable Resistance Training shows ads; KAI by Keep Labs does not.
Which is updated more often, KAI by Keep Labs or Variable Resistance Training?
KAI by Keep Labs ships an update every 3 weeks, and Variable Resistance Training every 6 days. Most recently, KAI by Keep Labs was updated on October 9, 2026 and Variable Resistance Training on October 10, 2026.

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