[tsac]

apparently they don't think older OS's are cost worthy for them to support.
They will support the latest Android which indicates to me any phone could be obsolete with their attitude.
It might be better to use a different app to do what you need. If they drop the amount of customers with out concern it looks like all they are doing is following a path to eventual destruction.

The full list of operating systems WhatsApp will stop supporting is:
Android 2.1 and Android 2.2
Blackberry OS 7 and earlier
Blackberry 10
Nokia S40
Nokia Symbian S60
Windows Phone 7.1

I would not use the app with that direction.