Microsoft confirms Windows Insider app is no longer required with Build 14327 & higher
Today, Microsoft has rolled out Build 14328 for Insiders on both PC & Mobile. Microsoft has confirmed that preview app will no longer be required as the Windows 10 Insider Preview Ring selector is now available from the Update & Security settings just like on Windows 10 PC. The Preview Ring selector slider allows you to choose Rings based on your preference. Until today Microsoft never reported it official, But Microsoft has now confirmed that Windows Insider app is not needed for the Build 14327 and higher and this Ring selector is functional.
Windows Insider Program settings page:
We have moved the Windows Insider Program settings to its own settings page. This is where you can go to join the Windows Insider Program (or stop receiving Insider Preview builds) and adjust which ring you are in. On Mobile – for Build 14327 and higher, the Windows Insider app is no longer required. To get to this new page, go to Settings > Update & security > Windows Insider Program.