it's not windows phone per se. it's windows mobile. it's not your fault. it's microsoft that come up with confusing name, and not backward compatible OS.

whatsapp come out after they buried windows mobile. it's a normal business strategy not to develop for obsolete OS, or discontinue support for obsolete OS.

just get android for your HD2.

anyway, i was wondering, you can call htc sensation as andriod phone, call hd2 as windows mobile phone. but can you call htc hd7 as windows phone phone? or windows phone 7 phone? see.. they try to make everybody confuse.

maybe in malay ok lah. talipon android, talipon windows mobile and talipon windows phone.