OpusTel vs DUO Holding
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OpusTel
This app provides a real Swiss international telephone number for secure VoIP calls on iOS devices. It offers HD audio quality, free global calls between users, and call recording capabilities, all with a focus on user privacy.
- Real Swiss international telephone number
- Secure VoIP calls
- HD high-definition audio quality
- Free global calls between users
- Call recording
- Conference calls
- Automatic language selection
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OpusTel OpusTel is the mobile phone App for iPhone, iPod and iPad, permitting one to use a real Swiss international telephone number, e.g. 0041 41 520 60 00. It allows one to make and to receive secure VoIP calls from any iOS device using 5G/4G/3G/UMTS or Wi-Fi Internet connectivity. It was developed with the focus on privacy. Features: 1. Secure incoming and outgoing calls 2. Incomming calls are free of charge (no roamingcosts) 2. HD high-definition audio quality with the G722 and Opus codec 3. Free global calls from OpusTel to OpusTel 4. Easy transfer calls to any telephone number 5. Ability to record incoming and outgoing calls 6. Conference calls 7. Automatic language selection based on handy language (15 languages like EN, DE, CN, FR, ES, IT ...)
DUO Holding
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Hol dir die DUO App! Jetzt Punkte sammeln und tolle Prämien kassieren! Auf Freunde des Hauses DUO warten attraktive Prämien wie Tankgutscheine, Wellnessgutscheine, Gewinnspiele, Einkaufsgutscheine und vieles mehr. Also gleich die kostenlose App runterladen und Punkte sammeln …
Screenshots
Verdict
The clearest difference is update cadence: DUO Holding at every 6 weeks against OpusTel's every 14 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.
OpusTel ships an update every 14 months, DUO Holding every 6 weeks. The most recent releases landed on August 29, 2026 and September 14, 2026 respectively.
| Parameter | OpusTel | DUO Holding |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (6 ratings) — better | — |
| Positive reviews | 80.0% of reviews | — |
| Number of ratings | 6 — better | — |
| Update frequency | Every 14 months | Every 6 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone | iPhone, iPod — better |
| Requires iOS | 16.0 | 15.1 — better |
| Further details — not scored | ||
| Size | 98 MB | 47 MB |
| Age rating | 4+ | 4+ |
| Developer | OpusTel | DUO Holding GmbH |
In-app purchases
OpusTel
No in-app purchases
DUO Holding
No in-app purchases
