MyWiFi Caller

MyWiFi Caller – Is our WiFi Calling app that provides voice connectivity when the user is in WiFi coverage and connected to that network. MyWiFi Caller app is simply downloaded from either the Play store or App store and following a simple registration process, available to Gamma mobile subscribers only, and the user is ready to go. Calls are made over the native dialler and are written to the device’s standard call log, calls will be billed as for standard mobile calls

MyWiFi Caller is for mobile users who want improved indoor coverage on their mobile devices using existing WiFi networks where the mobile network provides no or marginal coverage. Unlike other mobile network operators, our OTT (over the top) App works on a wide range of devices. MyWiFi Caller is integrated into the core of the mobile network, meaning that there is no need for an additional number, email addresses and separate billing when MyWiFiCaller is being used.

MyWiFi Caller App can be accessed from either the Google play store or the Apple App store by searching 'MyWiFiCaller'.

Getting Started


Compatible mobile network tariff. – Ask your mobile provider to find out if your tariff is compatible.

A handset using Android 5.0 and above

A handset using Apple 10 and above


You will need:

Your mobile number

To be in a WiFi (device needs to be registered to that WiFi network) and mobile coverage area Download the MyWiFi Caller App onto the device

Follow the on-screen prompts

Using MyWiFi Caller

The app needs to activate in the background for the user to be able to use MyWiFiCaller. Provided MyWiFiCaller is active, and the device is connected to a WiFi network all voice calls will be routed over the WiFi network even if there is mobile network coverage.


The native dialler and contact list can be used when using MyWiFi Caller. Once a number has been dialled, the MyWiFi Caller call control screen is displayed rather than the native call control screen. The functionality on this screen includes:

  • Call mute

  • Call forward

  • Loudspeaker


Provided a contact is stored in the device the native dialler can be used. However on the initial call to a contact the long press function will need to be used to write the MyWiFi Caller contact into the contact details. It is stored as an additional number in the contact, labelled MyWiFi Caller.

If the contact is not in the standard contact list, then it will need to be added, or the MyWiFi Caller dialler will need to be used. All calls made using the MyWiFi Caller dialler will be written to the native call log.

Once a number has been dialled, the MyWiFiCaller call control screen is displayed rather than the native call control screen. The functionality on this screen includes:

  • Call mute

  • Call forward

  • Loudspeaker

Frequently ask questions

1. What devices can I use?
MyWiFi Caller is available on Apple devices iOS 10 and above and Android devices OS 5.0 and above.

2. How do I subscribe to MyWiFi Caller?
MyWiFiCaller is not a subscription service. It's FOC to the standard Gamma mobile service.

3. How do I access MyWiFi Caller?
MyWiFi Caller app can be downloaded from either the Google Play store or the Apple App Store by keying in the devices search field ‘mywificaller’. Once installed you will be asked to register, all you need to do is follow the instructions on the device.

4. I have an Apple device how do I know I am using MyWiFi Caller?
There is a tick icon that appears on the top left-hand side of the notification bar. When you are making a call you will need to use the long press function and select the MyWiFiCaller labelled number for that contact. When you receive a call the call control screen is different from the standard Apple call control screen.

5. I have an Android device how do I know that I am using MyWiFi Caller?
There is a tick icon that appears on the top left-hand side of the notification bar. When dialling or receiving a call the call control screen is different to your normal device's call control screen. For incoming calls, you are unable to select a different ringtone from the standard MyWiFiCaller ringtone.

6. Can I change the ringtone from the standard?

7. Will I be charged for making a call using MyWiFi Caller?
Your normal tariff for the UK call rates apply.

8. What about when I am roaming?
When roaming and you are connected to a WiFi network you will be charged at your tariff’s UK rates.

9. Can I use my number?
Yes, you retain your number when using MyWiFi Caller.

10. Can I use the App on more than one handset?
No, if you register the same number on another handset, it will de-register the App on the original handset.

11. How do I de-register the device?
Delete the App from your device.

12. If a make a call in a WiFi area and move into a normal mobile coverage without WiFi will the call remain connected?
No, the call will be dropped, and you will need to re-dial.

13. Can I send and receive SMS using MyWiFi Caller?
No, if there isn’t any underlying mobile network, such as in the Underground, then you will not be able to send or receive SMS. However, even if there is a small amount of Gamma mobile coverage, you will be able to.

14. Will I get voicemail notifications?
Yes, you are still able to get voicemail notifications. However, if you have set up SMS notifications depending on the underlying signal of the Gamma mobile network, you may experience a delay. Gamma’s voicemail platform allows you to set a callback alert, whereby the voicemail platform will call you with the message.

15. Am I able to make 999 calls?
Yes, provided that there is any standard mobile coverage from any mobile network you can call the emergency numbers 999, 112 & 18000.

16. Does the App consume more battery?
Our testing hasn’t shown a noticeable deterioration of battery life. However, you should expect a small amount, about the same as you would leaving open an App like Whatsapp. If you are in a variable area may even see an improvement due to the device not constantly searching for the mobile network.

17. What about battery optimisation settings?
If you have battery optimisation set on your phone, you will be requested that this is ignored for MyWiFi Caller. You must allow this or registration will not continue.

18. Will MyWiFi Caller work on dual SIM handsets?
Yes, however if you have it toggled “On” all calls will be sent over the Gamma number. If you would like to use your other number you will need to toggle MyWiFi Caller “Off” in the App.

19. What is the minimum bandwith I need from my broadband
The call quality will depend on a number of factors such has how many people are using you connection at the same time you want to, how fast your connectivity is. However, a typical home broadband connection should be enough under normal usage to be able to use MyWiFi Caller.

20. I do not hear an engage tone on some calls
On some occasions when the number you call is engaged and does not have voicemail set up, then the call will end without any announcement. Please redial the number.

21. How do I restrict my number from being shown when I make a call with MyWiFi Caller
Prefix the dialled number with 141 and your mobile number will not be shown. This must be done for each call from the MyWiFi Caller that is made.

22. I am abroad using MyWiFi Caller, what international prefix do I need to use.
Always use the prefix of the country you are calling, even if you are in that country as the App always assumes the user is in the UK.

23. Can I use my defined speed dial codes from MyWiFi Caller
Yes, if you have assigned any contacts to a speed dial number, these will still work from MyWiFi Caller. The speed dial for voicemail (long press keypad “1”) cannot be integrated into MyWiFi Caller on the Android App.

24. Can I use GSM codes from MyWiFi Caller (shortcodes typically starting with “*” or “#”)
Yes, MyWiFi Caller will send them over the standard mobile network if coverage is available.

25. Will MyWiFi Caller stop calls from numbers I have blocked (added to the auto-reject list)?
Yes on iPhones, but not on Android handsets as MyWiFi Caller is not able to access the auto-reject list (blocked contacts).

26. There is an echo when I am using MyWiFi Caller
If you are hearing the echo ask the person you are calling to turn down their speaker volume. If the person you are calling is hearing an echo remove the handsfree kit (provided you are not driving) or headset if you are using a loudspeaker turn the volume down if that doesn’t work stop using the loudspeaker

27. I am using an iPhone, and my calls are persistently dropping after a minute
If you are in a weak WiFi area and have WiFi assist on the device will fall back onto the mobile network, and the call will drop. Switch off mobile data in your app settings. On your handset go to settings and scroll down until you see MyWiFi Caller tap on it and toggle off mobile data.

28. Can I use MyWiFi Caller and Connect?
No these are currently incompatible. To be able to use WiFi calling on connect please use the Horizon App.