Today, Instagram celebrates its 10th birthday. To celebrate, the social networking app has been updated today with several useful features, including the ability to display past stories on a map and an automatic filter that hides malicious messages. But one secret new feature in particular will excite longtime Instagram users, or those eager to customize their iOS home screen.

Starting with this update, iOS users can now change Instagram's app icon from several different options. There are black and white as well as alternative gradient versions, including Pride's Rainbow. The four most interesting, however, are the Instagram app icons of the past.

Instagram's old Polaroid-inspired icons appear here in several different flavors: the classic brown and beige skeuomorphic camera that began being used in 2010, and the revised version the app adopted between 2011 and 2016 are.

But even before that, personally speaking, there are two app icons that I don't recall ever seeing: one shows the familiar Polaroid camera as is, and the other (aptly titled Codename) is a nondescript black camera icon that was used only during Instagram's development The other is a nondescript black camera icon that was used only during the development of Instagram.

These icons can be used to give a nostalgic touch to the home screen. And especially so if you've been hard at work customizing your iPhone's home screen to look like the early days of Apple smartphones, as some have been doing since the release of iOS 14 last month.

To change the Instagram icon on your phone, make sure the app is updated to the latest version and head to Settings within the app, which is accessed by going to your profile, tapping the hamburger menu in the upper right corner, then tap Settings at the top of the list of options.

Once in the settings screen, scroll up, even though you are at the top of the page. As you scroll, you will see some cheeky emojis encouraging you to keep scrolling, and when you reach the top, you will be taken to a secret app icon page.

Unfortunately, and not surprisingly, this feature is for iOS users only. We updated to the latest version of the app on Android and the ability to change the icon does not appear to exist yet. We hope that eventually Instagram will give Android users the same love.