# Nix Solo — Real-time hydration data

> Real-time sweat analysis for personalized hydration during exercise. (iPhone/iPad app by Nix, Inc..)

- Source: https://appshunter.io/ios/app/nix-solo/id1632680170 (this page in markdown: same URL + `.md`)
- Developer: [Nix, Inc.](https://appshunter.io/developer/1625732872)
- Category: Health & Fitness
- Price: Free
- Rating: 4.80/5 from 55 App Store ratings · 21 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.1 · 65 MB
- Languages: American English
- Released: 2022-11-22
- Data updated: 2026-09-08
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/nix-solo/id1632680170/reviews.md

## What is Nix Solo?

To train at your peak, you can’t just train hard. You need to train in a way that’s informed by your personal biology.

The Nix Solo app allows users to monitor their own personal fluid and electrolyte losses in real time during a workout using the Nix Hydration Biosensor. This companion app provides valuable insight into their unique sweat composition and individual hydration needs based on their personal biology.

At Nix, we built the first biosensor to analyze sweat and provide endurance athletes with personal hydration data – scientifically validated, and delivered in real time.

Once paired with the Nix Hydration Biosensor, you are on your way to understanding your hydration needs with Nix Solo, our individual monitoring app. We’re the first hydration biosensor of its kind — the only pod, patch, and free app combination to:

- Evaluate the electrochemical biomarkers in your sweat
- Send real-time updates to your phone, Apple Watch, Garmin Watch, or Garmin Bike Computer
- Correlate your sweat data and your training environment with the Nix Index – a composite index of six environmental factors: temperature, humidity, dew point, altitude, wind speed, and solar load
- Provide post workout Sweat Intelligence via insights on your Sweat Profile including fluid loss rate, electrolyte loss rate and sweat composition metrics

Before your workout, tell the Nix Solo app what type of workout you’re doing and what you’ll be hydrating with. You can also consult the Nix Index to see how your environment impacts your hydration needs.

Once you start sweating, our single-use patch begins measuring and analyzing your fluid and electrolyte losses minute by minute- metrics that represent your unique “sweat composition.” This data is instantly streamed to our app, and can also be shared with devices like your Apple Watch, Garmin Watch, and Garmin bike computer.

The result is knowing when, what, and how much to drink in real time to enhance both safety and performance.

## Key features

- Real-time fluid and electrolyte loss monitoring
- Personalized sweat composition insights
- Correlates sweat data with environmental factors (Nix Index)
- Post-workout Sweat Intelligence reports
- Integration with Apple Watch and Garmin devices
- Workout type and hydration input

## Recent user reviews (10 of 21)

All indexed reviews: https://appshunter.io/ios/app/nix-solo/id1632680170/reviews.md

### 5/5 — No bugs as of 7/10/25, massively insightful data

*2025-07-10*

I’ve been using nix for the past 6 weeks and am blown away by the insights. I haven’t had any app crashes or bugs that I’ve seen on the other reviews. I have used whoop, garmin, levels, 8sleep, aura etc and this interface and usability is on par, or much better in some cases (garmin connect). I’m not currently training for a race, but this tool has almost given me a reason to sign up for another. Living on the lake outside of Houston, the Nix index is 100 on most of my workouts and I sweat considerably more than I would have ever imagined. Like 54oz doing yard work is nuts. Also, the breakdowns of how much of each electrolyte is very insightful and helpful in determining which drink and how much to consume before, during and after. I love this product and really glad it exists. I’m surprised it’s not a bigger deal than it is already.

### 1/5 — Unresponsive

*2025-06-15*

The app was working fine. Now that it asked for update it won’t recognize my password or email.  I have tried resetting my password and app to no avail.

### 3/5 — Good intentions, lots of bugs

*2024-09-01*

App crashed via Bluetooth connectivity during a 98°F ultra marathon yesterday so I couldn’t add fluid replenishment throughout the day; and it wouldn’t save my workout or reconnect to the Nix pod until I restarted my phone. I was at least able to retrieve sweat loss data after my run, but it added five hours of runtime (15.5 hours instead of what should’ve been 10.5, because the app wouldn’t let me save the workout until hours after). I would love to be able to edit the workout time, but that’s not an option. Also, regarding editing, I’ve tried to edit fluid replenishment and workout name, but it never saves the new edited data. Sharable graphics still isn’t working as well. Please work out these bugs because this is such a great tool when it’s working properly! Love being able to track my sweat loss; it really makes a difference in recovery after ultra marathons.

### 3/5 — Use the Insights After Your Workout

*2024-07-17*

This app is not very good as it crashes all the time during workouts. It also doesn’t notify you very well even when it is running. So I have stopped relying on it to cue me when to drink water. Instead I’ve used the overall electrolyte and fluid loss data to learn how to better hydrate during my workout. Even if the the app crashes during a workout, just restart the app and it will still download the data from the sensor. So you can collect workouts over time to learn how much you expell in various conditions. Just don’t expect it to notify you properly during a workout. Still very insightful data.

### 1/5 — Buggy Making it less than Worthless

*2024-07-06*

I can’t get the app to save any data from a full workout. Starts fine and can watch it work for a bit then at end of workout the app says ‘something went wrong’. There is no option to save what it has... only option is to discard workout!?!? Restarting the app and it instantly reconnects and says the patch needs to be replaced… with almost no information presented to user it appears that the patch gets saturated and then app just dumps all the data. I guess I have to stop workout early to save any data?

### 1/5 — Poor application and UX

*2024-06-04*

I wanted to like NIX. After multiple iOS installations I still am unable to properly set up my profile. The app lacks basic user friendly capabilities, it’s confusing and I am constantly being promoted to re-add the NIX device! The app UX is poor which leads me to be unable to use this device…

### 5/5 — Re-review

*2024-05-12*

Back to correct my negative review. The sensor works and upon my second use, it recorded my sweat profile and synced with my Garmin watch.

### 1/5 — Dumpster fire of an app

*2024-05-04*

This app is down right terrible. I got the Nix pod a year ago and I could never get it to work. So I throw it in a drawer and forgot about it. 

I just pulled it back out thinking “maybe a year later they actually got it to work properly.” I was wrong. Not only does the pod have massive issues with connectivity, I couldn’t even edit the name of my pod. The app is that poorly made—there’s no save/submit/done/etc to complete the name change. Return doesn’t even work. So you’re only option is to hit the back arrow.

### 1/5 — Worthless

*2024-02-15*

Couldn’t keep the device connected. When I finally got it to work, the data is pretty worthless. Don’t bother until they make it a functioning product.

### 1/5 — Not sure about this

*2024-02-12*

I’ve had my device for 2 months now. Honestly, I can’t make sense of what it is telling me. They should have a video to teach you how to use it including calibration. I should be able to calibrate by drinking a specific amount of fluid, such as a 16 oz bottle, with a specific electrolyte, and doing a specific workout, such as 1 hour on a bike at a specific power level, such as 130 watts on an indoor trainer. Without that I don’t trust what this gizmo is telling me - it contradicts what my cycling coaches tell me. Coaches tell me to raise my intake more than this device.  Pods are too expensive - $25.00 per workout is a lot.

## Frequently asked questions about Nix Solo

### What does the Nix Solo app do?

The Nix Solo app works with the Nix Hydration Biosensor to monitor your personal fluid and electrolyte losses in real-time during workouts. It provides insights into your unique sweat composition and individual hydration needs based on your personal biology and training environment.

### How does the Nix Solo app provide hydration data?

The app pairs with the Nix Hydration Biosensor, which analyzes electrochemical biomarkers in your sweat. This data is streamed in real-time to the app, and can also be sent to connected devices like Apple Watch and Garmin watches. It correlates this sweat data with environmental factors to provide a comprehensive hydration picture.

### Is the Nix Solo app free to use?

Yes, the Nix Solo app is free to download and use. The app itself does not have any associated costs. The Nix Hydration Biosensor and its single-use patches are separate hardware components that need to be purchased.

### What devices is the Nix Solo app compatible with?

The Nix Solo app can send real-time updates to your phone, Apple Watch, Garmin Watch, or Garmin Bike Computer. This allows for seamless integration of your hydration data into your existing training ecosystem.

### What kind of insights can I get from the Nix Solo app?

The app provides real-time updates on your fluid and electrolyte losses, allowing you to know when, what, and how much to drink. Post-workout, you receive 'Sweat Intelligence' with insights on your Sweat Profile, including fluid loss rate, electrolyte loss rate, and sweat composition metrics, helping to enhance both safety and performance.

## Version history (last 5 releases)

### 3.45 — 2026-08-27

- Minor bug fixes

### 3.44 — 2026-08-09

- Minor bug fixes and performance improvements

### 3.42 — 2026-08-06

- Minor bug fixes

### 3.41 — 2026-06-18

- Minor bug fixes and performance improvements

### 3.40 — 2026-06-03

- Minor bug fixes

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-08.*