Frontier X vs Milo Link
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Frontier X
Track your heart health and exercise performance with a smart chest strap monitor. Gain detailed insights into heart rate, rhythms, and training load. Receive personalized feedback and alerts to optimize your workouts and understand your body better.
- Heart Health Monitoring
- Real-time Heart Rate & HRV
- Breathing Rate & Strain Tracking
- Activity Recording (24hrs)
- Personalized Vibration Alerts
- AI-enabled Training Insights
- Metabolic Profile Analytics (Premium)
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With your Frontier X/X2, track your activity including exercise, rest or sleep to get detailed insights on heart health and exercise performance. This companion app allows you to connect with Frontier X2 - a revolutionary chest strap wearable smart heart monitor and view your recorded data. Trusted by world-class athletes across the globe, the Frontier X2 is a chest-worn Smart Heart Monitor that provides in-depth real-time feedback on your heart health. It can monitor your: - Heart Health - Heart Rate - Heart Rate Variability (HRV) - Breathing Rate - Strain - Rhythms - Training Load - Calories - Stress, and a lot more. • Accurately record your activity like exercise, running, cycling, resting, sleeping, meditation, etc for up to 24hrs with comprehensive heart health insights. • Spot changes in your heart health with Rhythm and Strain. • Train in the right zone without distractions with real-time, personalized, and discreet vibration alerts. • Add health event tags to help you understand how lifestyle choices and behavior affect your health. • Seamlessly integrate with Bluetooth-enabled wearables and third-party devices such as GPS sports watches, bike computers, and more. • AI-enabled algorithms - Receive post-activity training insights, recommendations, and weekly goals. • Frontier X integrates with HealthKit to export your Frontier X activities into the Health app and to read heart rate and biometric data. • IP67 Waterproof up to 1.5 M • Battery: 14+ days of typical use Now get deeper insights and data with Frontier Premium Subscription*: Metabolic Profile Analytics: Track training intensity and the impact of lifestyle changes on metabolic health with key metrics like VO2 Max, VO2 Zones, Oxygen Uptake, and Ventilatory Thresholds (VTs). VO2 Max: Get the most accurate real-time Vo2 Max data. While other wearables estimate using motion and heart rate, our advanced algorithms provides precise Vo2 Max readings outside of a lab, tracking cardiovascular efficiency and endurance potential. Readiness Score: Determine if your body is ready for peak performance or needs recovery. Advanced algorithms use heart rate, heart rate variability (HRV) to guide your daily activities and training. Sleep Stage Analysis: Get a comprehensive understanding of your sleep quality (Webapp). With Frontier's Premium subscription and Metabolic Profile Analysis, tracking your VO₂ max becomes simpler and more precise. *A Paid Frontier Premium subscription is required to access the full feature set . The Premium feature subscription comes with a complimentary 7 days free trial, and continue at a minimal monthly cost starting from USD 14.99, or opt for an annual plan for substantial savings. Please note that prices may fluctuate based on your geographical location, currency, and current exchange rates The Terms of use are available in the app and our website: https://in.fourthfrontier.com/pages/terms-of-use About Fourth Frontier Fourth Frontier is an innovative health-tech company focused on revolutionizing heart health monitoring with its cutting-edge wearable technology. We are the World’s First Smart Heart Monitor. With over 5 billion heartbeats recorded from 120,000+ users across 50+ countries, we are empowering users to understand and manage their heart health in real-time. These features make the Frontier App a comprehensive tool for heart health management and fitness improvement. Download the app today and access the most accurate heart health data available. Apps available for iPhone and Apple Watch.
Milo Link
This app serves as an official companion for a device, allowing users to update its software, customize settings like language, and access offline information. It ensures the device receives new features and performance improvements.
- Update device software
- Customize device language
- Access offline information
- Learn about device features
- Performance enhancements
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The official companion app for updating, customizing, and learning about your Milo! - Keep your Milo updated with new features and performance enhancements - Change Milo's language - Packed with information that's available offline, for access off-the-grid
Screenshots
Verdict
The clearest difference is rating: Frontier X at 4.6 against Milo Link's 4.1. Frontier X also leads on review sentiment (82% vs 57%) and ratings volume (317 vs 28). Milo Link's advantage is in-app purchases (none vs 2) and iOS requirement (12.0 vs 16.0). On price, update cadence, ads 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
Both are free to download. Frontier X sells 2 in-app purchases, starting at $14.99 per month. Milo Link asks for nothing beyond the download.
Frontier X holds the better App Store score, 4.6 against 4.1. That said, the two scores are not equally well evidenced: Frontier X has 317 ratings behind it against 28, so its average is the more settled of the two. Written reviews point the same way: 82% of Frontier X's written reviews are positive against 57% of Milo Link's.
Frontier X ships an update every 3 weeks, Milo Link monthly. The most recent releases landed on September 29, 2026 and September 6, 2026 respectively.
| Parameter | Frontier X | Milo Link |
|---|---|---|
| Price | Free | Free |
| Rating | 4.6 (317 ratings) — better | 4.1 (28 ratings) |
| Positive reviews | 81.8% of reviews — better | 57.1% of reviews |
| Number of ratings | 317 — better | 28 |
| Update frequency | Every 3 weeks — better | Monthly |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, Apple Watch | iPhone, iPod |
| Requires iOS | 16.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 571 MB | 88 MB |
| Age rating | 4+ | 4+ |
| Developer | Fourthfrontier | Loose Cannon Systems |
Customer experience
Frontier X
Milo Link
Bugs and requests
Frontier X
Reported bugs
4 issues- ECG stopped working
- Inaccurate breathing rate and other metrics
- Inability to edit activity details for indoor workouts
- Syncing issues with Garmin devices after firmware updates
Requested features
6 requests- Add interval markers
- Improve integration with Apple Fitness/Fitness+
- Add support for ANT+
- Improve compatibility with other fitness apps and devices
- Add more customization options for workouts
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- Improve data visualization and analysis tools
Milo Link
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Frontier X
- Monthly7 Days trial$14.991 Month
- Yearly7 Days trial$119.991 Year
Milo Link
No in-app purchases









