SIGMA LINK vs CKcardio
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SIGMA LINK
Easily transfer training data from compatible devices to your smartphone. View personal bests, statistics, and completed tracks. Sync all your training data, workouts, and sport profiles with cloud integration for constant access.
- Transfer training units
- View training statistics
- Track personal bests
- Manage device settings
- Sync with SIGMA CLOUD
- Access workouts and sport profiles
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The SIGMA LINK App is your supplement to the DATA CENTER and the fastest and easiest way to access your training data. With SIGMA LINK, you can transfer all your training units from a compatible SIGMA product to your smartphone. In addition to this, device settings can be made directly in the app. Besides the individual trainings, the app also shows you personal best performances, training statistics as well as completed tracks. With the SIGMA CLOUD integration, you can sync all your training data, workouts, sport profiles and tracks now with the new LINK App. So your data is available on your iPhone all the time. Enjoy the new SIGMA LINK App! NOTE: Apple doesn't support NFC. If you want to show your data from another bike computer, please use our SIGMA CLOUD to sync your data.
CKcardio
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CKcardio – Heart Rate Training with Zones CKcardio makes heart rate training simple, precise, and motivating. Whether you're running, cycling, doing HIIT, or training freely — keep your heart rate zones in view and train exactly where it counts. Live heart rate across five customizable training zones Rest, Recovery, Fat Burn, Anaerobic, and Maximum — set the exact heart rate range for each zone yourself, so the app adapts precisely to your fitness level. Support for Bluetooth chest straps and Apple Watch Connect your heart rate strap (e.g. Polar) or use your Apple Watch directly. If you often train in the same place with many sensors nearby — like at the gym — CKcardio remembers your sensor and highlights it the next time you search, so you can find it instantly. Guided and custom training programs Choose from suggested programs or build your own — with as many phases as you like, custom duration, and a target zone for each phase. You can also record a free workout and save it afterward as a repeatable program, with a handy smoothing feature for clean, rounded phase times. Training continues in the background Lock your iPhone or switch apps — your workout and heart rate tracking keep running reliably. An audio cue announces upcoming zone changes, so you don't have to keep checking the screen. A full summary after every workout See at a glance how much time you spent in your target zone, plus average, maximum, and minimum heart rate, and your estimated calorie burn. Your complete training history stays available to review anytime. Saves to Apple Health Your workouts are optionally saved directly to Apple Health, giving you one central view of your fitness. CKcardio Pro CKcardio Pro unlocks all premium training programs, lets you create and import unlimited custom workouts, and adds new programs regularly. Try Pro free — cancel anytime. Available in many languages CKcardio is available in over 20 languages. Download CKcardio now and train smarter with your heart rate as your guide.
Screenshots
Verdict
The clearest difference is in-app purchases: SIGMA LINK at none against CKcardio's 2. SIGMA LINK also leads on iOS requirement (12.0 vs 26.5). CKcardio's advantage is update cadence (fortnightly vs every 4 months). On price, 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. CKcardio sells 2 in-app purchases, starting at $0.99 per month. SIGMA LINK asks for nothing beyond the download.
SIGMA LINK ships an update every 4 months, CKcardio fortnightly. The most recent releases landed on October 20, 2026 and October 9, 2026 respectively.
| Parameter | SIGMA LINK | CKcardio |
|---|---|---|
| Price | Free | Free |
| Rating | 1.5 (8 ratings) — better | — |
| Positive reviews | 9.0% of reviews | — |
| Number of ratings | 8 — better | — |
| Update frequency | Every 4 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 12.0 — better | 26.5 |
| Further details — not scored | ||
| Size | 76 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | SIGMA-ELEKTRO GmbH | Christian Kany |
In-app purchases
SIGMA LINK
No in-app purchases
CKcardio
- Mothly subscription7 Days trial$0.991 Month
- Year subscription7 Days trial$8.991 Year









