OSTConf vs Kalank
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OSTConf
Configure your dive computer settings and parameters wirelessly. Update date, time, custom text, gas mixes, and deco settings. Compatible with recent Bluetooth-enabled dive computers.
- Read and modify settings
- Update date and time
- Set custom text
- Configure gas mixes
- Set deco parameters
- Upgrade firmware
- Retrieve device information
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OSTConf is an application for configuring your OSTC dive computer. It allows you to read and modify settings and parameters of dive computers manufactured by heinrichs weikamp GmbH. Using Bluetooth LE technology, you can retrieve device information, update date and time, custom text, set up your gas mixes and deco parameters as well as upgrading the firmware. OSTConf is compatible with recent Bluetooth-capable OSTC dive computers such as OSTC 2, OSTC plus, OSTC sport, OSTC TR, and OSTC 4. Note that due to the iOS hardware only OSTC devices with BLE are supported. OSTC4: The firmware file contains up to three parts. Please start the firmware update multiple times to ensure that all parts are updated.
Kalank
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Kalank is the next-generation dive logbook: record, import, book and share all your underwater activities: scuba diving, snorkeling, freediving... YOUR LOGBOOK, ALWAYS UP TO DATE Log every dive in seconds: location, depth, duration, conditions, gear… Your dives are numbered, organized and available anytime, even offline on the boat. IMPORT FROM YOUR DIVE COMPUTER Connect your dive computer via Bluetooth or import a file: your dives land in your logbook automatically, with all their data. No more manual entry. BOOK YOUR DIVES IN A FEW TAPS Find a dive center, pick your trip, course or gear, and book directly from the app — for yourself or for someone else. CATALOG YOUR SIGHTINGS Fish, turtles, nudibranchs… Record the species you encounter on every dive and build your own underwater encyclopedia. SHARE YOUR ADVENTURES Find your dive buddies, follow their trips and keep your passion alive beyond the water. Whether you're a beginner in training or an experienced diver, Kalank is with you before, during and after every dive. Download Kalank and dive into the adventure.
Screenshots
Verdict
The clearest difference is update cadence: Kalank at every 3 weeks against OSTConf's every 5 months. On price, ads, in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.
OSTConf ships an update every 5 months, Kalank every 3 weeks. The most recent releases landed on October 6, 2026 and September 30, 2026 respectively.
| Parameter | OSTConf | Kalank |
|---|---|---|
| Price | Free | Free |
| Positive reviews | 25.0% of reviews | — |
| Update frequency | Every 5 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 16.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 3 MB | 5 MB |
| Age rating | 4+ | 4+ |
| Developer | Kai-Uwe Sattler | Andrea Esposito |
In-app purchases
OSTConf
No in-app purchases
Kalank
No in-app purchases









