# Duo Plus > Bluetooth helper app for iPhone to enable dual SIM, calls, SMS, and anti-lost features. (iPhone/iPad app by 文辉 刘.) - Source: https://appshunter.io/ios/app/duo-plus/id1062771049 (this page in markdown: same URL + `.md`) - Developer: [文辉 刘](https://appshunter.io/developer/827451377) - Category: Utilities, Lifestyle - Price: Free - Rating: 2.00/5 from 1 App Store ratings · 1 written reviews indexed - Age rating: 4+ - Requires: iOS 7.1 · 22 MB - Languages: Arabic, Dutch, English, French, German, Italian, Japanese, Korean, Russian, Chinese and 2 more - Released: 2016-01-21 - Data updated: 2026-06-10 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/duo-plus/id1062771049/reviews.md ## What is Duo Plus? Duo is an indispensable Bluetooth-based helper for your iPhone, while Duo plus is an assisting app designed for using Duo on iOS devices. Once paired with Duo via a specialized App, your iPhone will become Dual SIMs & Dual Standby, which allows to make phone calls and send SMS with any SIM card inserted in Duo. For the iOS devices without communication functions such as iPad and iPod Touch, Duo can enable them become a real phone. Phone Call & SMS When Duo is connected with your iPhone, contacts list will be synced. You only need to make phone calls and text messages on App as what you usually do on your phones. Duo App cannot edit contacts. If you want to edit contact information, please go to Contacts of your phone to make modifications. Regarding DuoPlus’s background audio play function:

The matched BLE gadget contains Anti-lost Alarm function.
It has 2 modes: Mutual Find and Lost Alarm.

A. Mutual Find Mode
After BLE gadget connected with App, in App’s Settings---More, you can enable “Find iPhone” feature, and select unique Ringtone for alarm from in-built ringtone list.
When user needs to find his misplaced iPhone (iPhone and BLE gadget stay connected), he can long press the camera button on BLE gadget for 4 seconds to make iPhone play selected Ringtone alarm, this audio sound will help to locate and find it. 
During Ringtone alarm playing period, if iPhone found, he can repress the camera button for about 4 seconds to mute and stop Ringtone playing.
Either App is running background or foreground, long press the camera button will make iPhone play this selected Ringtone alarm.

B. Lost Alarm Mode
When iPhone and BLE gadget lost connection (poor Bluetooth connection, App quit abnormally, long distance between each other), this selected alarm Ringtone will also be triggered to be played on iPhone to alert user, no matter App is running background or foreground.

 Regarding DuoPlus’s GPS function:
If iPhone and BLE gadget lost connection, App will use iPhone’s GPS to locate and record the current location of iPhone, in App’s Settings---Lost Records, this last connection location will be marked as Pinpoint on Map to help user backtracking it.


Related functions demonstration video as below:
https://youtu.be/HZbE4vaxKQw Supporting devices It supports Apple devices with iOS7.1 or above. (iPhone5, iPhone5c, iPhone5S, iPhone6, iPhone6 plus, iPhone6s, iPhone6s plus; iPad2 & above; iPad mini all series; iPod Touch5 & above) Notice: Continued use of GPS running in the background can dramatically decrease battery life. ## Key features - Dual SIM and Dual Standby on iPhone - Make calls and send SMS - Transforms iPads/iPods into phones - Anti-lost alarm (Mutual Find & Lost Alarm) - GPS location tracking for lost devices - Syncs contacts list ## Recent user reviews (1 of 1) All indexed reviews: https://appshunter.io/ios/app/duo-plus/id1062771049/reviews.md ### 2/5 — Please update the app *2019-02-28* This app need a update ## Frequently asked questions about Duo Plus ### Does Duo Plus have ads? No, Duo Plus does not contain advertisements, as indicated by the 'hasAds' flag being false. ### What devices support Duo Plus? Duo Plus supports Apple devices with iOS 7.1 or above, including various iPhone models, iPad 2 and above, all iPad mini series, and iPod Touch 5 and above. ### How does the anti-lost alarm work in Duo Plus? The anti-lost alarm has two modes: Mutual Find, where you can trigger an alarm on your iPhone from the BLE gadget to locate it, and Lost Alarm, which alerts you on your iPhone if the connection is lost. ### Can I edit contacts directly in Duo Plus? No, the Duo Plus app cannot edit contacts. To make any modifications to your contact information, you need to go to the Contacts app on your phone. ### What is the GPS function in Duo Plus used for? If the iPhone and BLE gadget lose connection, Duo Plus uses your iPhone's GPS to record and display the last known connection location on a map, helping you backtrack to find your device. ### How often is Duo Plus updated? The latest version of Duo Plus is 1.5, which was last updated on October 29, 2016. This indicates a less frequent update schedule. ### What is the user rating for Duo Plus? Duo Plus has a rating of 2.0 stars based on 1 rating. This suggests a low level of user satisfaction based on the available data. ### Does Duo Plus require a constant Bluetooth connection? Yes, Duo Plus relies on a Bluetooth connection to function for features like dual SIM, calls, SMS, and the anti-lost alarm. Continued use of GPS in the background can significantly decrease battery life. ## Version history (last 5 releases) ### 1.5 — 2016-10-29 This app has been updated by Apple to display the Apple Watch app icon. Compatible with iOS10 Update database of Carrier information to fix the bug that carrier title isn't displayed correctly in some areas General bug fixes and performance enhancements ### 1.4 — 2016-08-09 Bug Fixes · Block list now can work properly · The bug that one message received twice is now fixed · Wrong display of characters has been fixed · Useless and inaccurate functions are removed · Wrong display of French Carriers has been fixed Performence Enhancements · App runs more stable · New API is added for using in France · Update database of SMSC for improving message function in France ### 1.3 — 2016-07-12 1. Polish Franch language, enhance user experience under French language; 2. Fix the bug that Chinese character appears in other language environment; 3. Fix the bug that disorganized characters were shown in call records. ### 1.2 — 2016-06-12 1. Name and icon of contact will be displayed when you recieve a call. 2. Enhence the number attribution recognition in non-roaming condition. 3. The title of American Carriers can be displayed nomally. 4. Connection password can be reset. Protect your privacy in a better way. 5. Fix the bug of Chinese charaters appearing in Russian and Dutch language environment. 6. Enhance stability of the Duo Plus. ### 1.1 — 2016-04-26 New Login system, Contacts and black lists can be uploaded to Cloud Bug fixed lRepair wrong interface in Language option Traditional Chinese, Simplify Chinese and French is available Improve UI design lSmaller font size makes interface more comfortable lOptimize the interfaces of dialing and incoming call ## More apps by 文辉 刘 - [MNN Chat](https://appshunter.io/ios/app/mnn-chat/id6748348797) All apps by 文辉 刘: https://appshunter.io/developer/827451377 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*