Can I install whatsapp and other apps on blackberry lower range (curve,bold...

...series) handset without BBM pack? Can I install whatsapp and other apps on blackberry lower range (curve,bold series) handset without BBM pack?

Can I use the afore mentioned apps with a simple domain tarrif applicable? If yes, please guide me the procedure as I'm finding difficult to shell out money activating bbm every month. I have AirTel domain. Please guide me the steps or procedure if possible. Thank you. Good day. :)