# SmartLine Second Phone Number vs DDuet

The clearest difference is in-app purchases: DDuet at none against SmartLine Second Phone Number's 2. DDuet also leads on update cadence (every 6 days vs every 2 months). SmartLine Second Phone Number's advantage is iOS requirement (12.1 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. SmartLine Second Phone Number sells 2 in-app purchases, starting at $12.99 per month. DDuet asks for nothing beyond the download.

SmartLine Second Phone Number ships an update every 2 months, DDuet every 6 days. The most recent releases landed on October 26, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | SmartLine Second Phone Number | DDuet |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (44K ratings)](https://appshunter.io/ios/app/smartline-second-phone-number/id1161533637/reviews)** | — |
| Number of ratings | **44K** | — |
| Positive reviews | 15.5% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 6 days** |
| Monetization | Subscription | — |
| Size | 75 MB | 74 MB |
| Requires iOS | **12.1** | 17.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [GoDaddy.com, LLC](https://appshunter.io/developer/333201816) | [B3 Networks Pte Ltd](https://appshunter.io/developer/1322980713) |

## What reviewers say

### SmartLine Second Phone Number

[App page](https://appshunter.io/ios/app/smartline-second-phone-number/id1161533637)

Get a dedicated second phone number for your business to maintain privacy and professionalism. This app ensures calls are business-related, offers a spam filter, custom voicemail, and voicemail-to-text transcription. Manage your business communications efficiently with organized history and timely notifications.

**Highlights:** Dedicated business phone number, Professional call quality (not VoIP), Spam call filtering, Customizable voicemail greetings, Voicemail to text transcription, Set business hours for calls, Organized call and text history

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SmartLine Unlimited (Monthly) | $12.99 | per month |
| SmartLine Toll-Free | $19.99 | per month |

**What reviewers like**

- 🚀 Convenient business line
- 📝 Stores call/text history
- ⏱️ Ability to set business hours

**What reviewers complain about**

- 🐛 Unreliable text messaging
- 📞 Missed/dropped calls
- 🔔 Delayed/missing notifications
- 🤖 Poor customer support

**Reported bugs**

- Disappearing call/text history
- Incorrect number display on outgoing calls
- Failure to sync across devices

**Requested features**

- Ability to send multiple photos/files
- Improved caller ID display
- Option to have multiple voicemail greetings
- Compatibility with VPNs and older devices


### DDuet

[App page](https://appshunter.io/ios/app/dduet/id6755167747)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is SmartLine Second Phone Number free?

SmartLine Second Phone Number is free to download, with in-app purchases available.

### Is DDuet free?

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

### Do SmartLine Second Phone Number or DDuet have ads?

Neither SmartLine Second Phone Number nor DDuet shows ads.

### Which is updated more often, SmartLine Second Phone Number or DDuet?

SmartLine Second Phone Number ships an update every 2 months, and DDuet every 6 days. Most recently, SmartLine Second Phone Number was updated on October 26, 2026 and DDuet on October 8, 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.*