It is an application that lets you transfer large files including movies and application from one device to other faster than Bluetooth.
To download SHAREit, you can go to www.shareit.kim to get the direct link to download the .apk file for SHAREit and install it.
Yes, SHAREit is available for iOS as well. You can go to www.shareit.kim to know more about it.
The SHAREit application can send per file at >20 MB/second.
Yes, you can download SHAREit on Windows operating system as well.