How can I get BB apps from sources/websites except Blackberry world?

I have a z10 stl 100-2 and using it in Myanmar where there is no Blackberry store, BIS, BES. Also Blackberry World is never working. So I would like to know how can I get apps from other sources than Blackberry World. Now I seriously need to get working Viber app and other.
Please kindly advise me.

Thanks,
Lmm