Re: Help- need to install a hybrid OS7 on a Classic- for BIS.
I think your misunderstanding the way the app works. It uses your data plan to send and receive messages and other features offered. It was originally designed to not use the text feature on phones to avoid the charges most carriers add per message.
A lot of people try to bypass the BIS requirement and run into issues depending on the carrier. No clear answer on why. Some have avoided using BIS on OS 7 level software
The WhatsAPP web site indicates only BIS but the Appworld site indicates all OS10 devices work. The information is conflicting.
If you have not tried it yet, go for it and see how you make out.
Z10 on BES
Z10 on BIS