TempGrapher vs Frontier X
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
TempGrapher
Easily log your body temperature with a simple slider interface. View your temperature history as a line graph in both Celsius and Fahrenheit, with HealthKit support. Data is saved to your default calendar and can be shared via email or cloud services.
- Simple slider input for temperature
- Celsius/Fahrenheit conversion
- Line graph visualization
- HealthKit integration
- Calendar app data saving
- CSV data export
- Dark mode support
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TempGrapher is your body temperature tracking app. HealthKit support. This app has a very simple input method that just slide your finger on slider to choose your body temp.. No Keypad. And this app is converting between degrees Celsius to degrees Fahrenheit during input slider moving. And you can check your temperature record with line graph with the both of Celsius and Fahrenheit. Selection of the use of default Calendar App of iOS. Temperature data are saved at default Calendar App on iOS. You can check the date and data with default Calendar. and with using Cloud service, sharing of data will be available and you can referring the data from PC. Feature 1, There is a very simple user interface to input temperature data. 2, You can input notes. 3, The input range is between from 93.2 to 107.6 degrees Fahrenheit. (from34 to 42 degrees Celsius) with 0.1 degree interval. 4. Temperature data convert automatically between degrees Celsius to degrees Fahrenheit and record the both of data. 5, You can insert temp data. 6, There is a Reset menu to all data clear. 7, You can choose the font color for temperature display. There are White, Gray, Blue, Pink, Green and OFF. You can be hidden temp display by selecting OFF. 8, Dark mode support on iOS13. 9. Exporting stored data to mail in CSV format. 10, There is simple timer for five minute. A orange bar extend to the right. 11, HealthKit support.
Frontier X
Track your heart health and exercise performance with a smart chest strap wearable. Get detailed insights into heart rate, HRV, strain, and more, with personalized training feedback and alerts. Integrates with other devices and offers advanced analytics through a premium subscription.
- Heart health and performance tracking
- Real-time heart rate and HRV monitoring
- Personalized vibration alerts
- Activity recording up to 24 hours
- Integration with Bluetooth wearables
- AI-enabled training insights
- Metabolic Profile Analytics (Premium)
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With your Frontier X/X2/X3, 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/X3 - a revolutionary chest strap wearable smart heart monitor and view your recorded data. Trusted by world-class athletes across the globe, the Frontier X2/X3 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.
Screenshots
Verdict
The clearest difference is review sentiment: Frontier X at 82% against TempGrapher's 27%. Frontier X also leads on price (Free vs $0.99) and rating (4.6 vs 1.0). TempGrapher's advantage is in-app purchases (none vs 2) and iOS requirement (14.0 vs 16.0). On 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
Frontier X is free to download; TempGrapher costs $0.99 up front. Frontier X sells 2 in-app purchases, starting at $14.99 per month. TempGrapher asks for nothing beyond the download.
Frontier X holds the better App Store score, 4.6 against 1.0. That said, the two scores are not equally well evidenced: Frontier X has 318 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 27% of TempGrapher's written reviews are positive against 82% of Frontier X's.
TempGrapher ships an update every 3 months, Frontier X every 2 weeks. Both last shipped on October 30, 2026.
| Parameter | TempGrapher | Frontier X |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 1.0 (1 ratings) | 4.6 (318 ratings) — better |
| Positive reviews | 26.7% of reviews | 81.8% of reviews — better |
| Number of ratings | 1 | 318 — better |
| Update frequency | Every 3 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Freemium — better |
| Devices | iPhone, iPod | iPhone, Apple Watch |
| Requires iOS | 14.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 6 MB | 569 MB |
| Age rating | 4+ | 4+ |
| Developer | kazuhiko kuroda | Fourth Frontier Technologies Private Limited |
Customer experience
TempGrapher
Frontier X
Bugs and requests
TempGrapher
Not enough reviews yet to summarise bugs or 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
In-app purchases
TempGrapher
No in-app purchases
Frontier X
- Monthly7 Days trial$14.991 Month
- Yearly7 Days trial$119.991 Year








