# O2 Duration vs TeleCloud Pro

The clearest difference is price: TeleCloud Pro at Free against O2 Duration's $2.99. TeleCloud Pro also leads on rating (4.3 vs 1.0) and update cadence (every 3 months vs every 15 months). O2 Duration's advantage is iOS requirement (7.0 vs 16.0). On ads, in-app purchases and device support there is nothing between them.

TeleCloud Pro is free to download; O2 Duration costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

TeleCloud Pro holds the better App Store score, 4.3 against 1.0. Both are backed by a comparable volume of ratings — 1 and 4 respectively.

O2 Duration ships an update every 15 months, TeleCloud Pro every 3 months. The most recent releases landed on September 30, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | O2 Duration | TeleCloud Pro |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [1.0 (1 ratings)](https://appshunter.io/ios/app/o2-duration/id556420187/reviews) | **[4.3 (4 ratings)](https://appshunter.io/ios/app/telecloud-pro/id6458188171/reviews)** |
| Number of ratings | 1 | **4** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 15 months | **Every 3 months** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 114 MB |
| Requires iOS | **7.0** | 16.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [Advanced Aviation LLC](https://appshunter.io/developer/540245667) | [TeleCloud LLC (NJ)](https://appshunter.io/developer/1701088921) |

## What reviewers say

### O2 Duration

[App page](https://appshunter.io/ios/app/o2-duration/id556420187)

Calculate the approximate remaining oxygen in portable cylinders. Select your tank size, input current pressure and desired flow rate to see duration in minutes. Features a timer with alerts for low pressure.

**Highlights:** Oxygen cylinder duration calculation, Supports multiple cylinder sizes (A, B, D, E, G, H, K, M), Input current tank pressure, Input desired flow rate, Displays duration in minutes, Running timer with remaining time, Low pressure alerts (500lbs and 0lbs)

**Features:** macOS Compatibility

**In-app purchases:** none


### TeleCloud Pro

[App page](https://appshunter.io/ios/app/telecloud-pro/id6458188171)

This soft client extends your office phone system to your mobile device. Make and receive calls as if you were at your desk, and enjoy free app-to-app calls with other users. Access voicemails, view call history, and manage your greeting.

**Highlights:** Make/receive office calls on mobile, Free app-to-app calls, View voicemails, Access call history, Change greeting remotely, High-definition conversations

**In-app purchases:** none


## Frequently asked questions

### Is O2 Duration free?

O2 Duration costs $2.99, with no in-app purchases.

### Is TeleCloud Pro free?

TeleCloud Pro is free to download, with no in-app purchases.

### Which has better reviews, O2 Duration or TeleCloud Pro?

TeleCloud Pro is rated higher. O2 Duration averages 1.0 out of 5 from 1 ratings, while TeleCloud Pro averages 4.3 from 4 ratings.

### Do O2 Duration or TeleCloud Pro have ads?

Neither O2 Duration nor TeleCloud Pro shows ads.

### Which is updated more often, O2 Duration or TeleCloud Pro?

O2 Duration ships an update every 15 months, and TeleCloud Pro every 3 months. Most recently, O2 Duration was updated on September 30, 2026 and TeleCloud Pro on September 23, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*