What is the purpose of the Windows Insider app for Windows Phone launched yesterday?

[Windows Central Question]

http://www.windowscentral.com/phone-insider-app-windows-10-updated-renamed-windows-insider-microsoft-account

"phone insider" apps renamed the release Microsoft is "windows insider" app Yesterday
download it in given link and register your Microsoft account or domain account
And wait for preview release, me to also waiting

one Question
when I got windows phone 10 preview on my phone in india?

second Q:
what is the purpose of windows insider app?

third Q:
I open the apps and select the Microsoft account and enter my account then give login button after normally come previse page, I check my update it show no update is available?

how can I get windows 10 for my phone(Lumia 520)?

 

[Laura Knotek]

It is to allow one to get the Windows 10 preview for phones once it is released.

Windows 10 preview for phones will not be available until February 2015. It has not been released yet in any country.

http://www.windowscentral.com/phone...ted-renamed-windows-insider-microsoft-account