Dynamics 365 for phones and tablets after call app doesnt open

I installed the 365 app on my phone and online it is saying that after a phone call with your customer the application will prompt you to enter details about the phone call. So I tried this function but it didnt seemed to work on my android device. So I tried it on an Iphone and it still didnt work. We dont have a Windowsphone/tablet so I cant try that, but is this a bug or what is going on?

I made a new contact with my phone number, called it from another phone, but it didnt open the application after the phone call.

Here is the Website with the information saying it should open:

https://www.microsoft.com/en-us/dynamics/crm-customer-center/email-and-call-customers-in-dynamics-365-for-phones-and-tablets.aspx