Installing whatsapp and facetime

Hi. Vanakkam to everyone.

I have recently bought Apple Ipad mini 3.

The configuration is 64GB,IOS8.3, 1 GB ram.

This is my first apple product.Till now i have used windows and android phones.

My problem is that i cant get whatsapp and facetime apps on the app store.

i don't know what is the problem nor the solution.

i tried everything i could but still i cant see those names in app store.

Please help me out.

Thank you