The Phone Insider app was recently updated to Windows Insider app.
As you recall this app was released a few days before the Windows 10 event in Jan. but it only accepted login credentials from internal Microsoft accounts.
After this update and re-branding, while it still accepts internal Microsoft login credentials, it now accepts login credentials you and me.
You can also hit the "get preview builds" to see if there are any available builds to download.
It looks like we are near the public release of the first build of Windows 10 for phones.
Remember Joe Belfiore, stated during the Windows 10 event that we would get the preview build after the Seahawks win the SuperBowl.
As you may or may not know the SeaHawks lost, but I am sure we will still get the preview build right?... right???!