How to unlock all the birds on LOOPY BIRD on my IPhone?

I've been playing Loopy Bird and I NEED to know how to unlock the birds?

For everyone wondering how to get birds and backgrounds. Here's part of the list:

Loopy Bird - Reach 60
Crazy Bird - Reach 80
Mini Bird - Reach 100
Country Town - Reach 150
Volcano Island - Reach 200? - Reach 300? - Reach 500? - Reach 800? - Reach 900? - Reach 1000

After you get Crazy Bird things will get a little easier. Crazy Bird scores double points which means you'll only have to get to 50 with Crazy Bird to unlock Mini Bird and once you have mini bird things will be way easier.