Google has rolled out a new update for the Gmail app for Android which replaces the "+" icon with a new "Compose" button. The app featured a floating action button with the "+" symbol in the bottom-right corner since its Material Design 2.0 refresh last year. With the latest update though, that has now changed to an oblong-shaped "Compose" button with a pencil icon. The button will automatically transition to the pencil icon while scrolling.
Its a subtle change but one that should make it easier for people who are not familiar with the Gmail app to know which button they need to press to quickly compose an email. Other Google apps like Drive still continue to use the older "+" icon for creating new documents and folders.
Given that Google follows the same design language for Gmail on Android and on the web, it is possible that we could see the new oblong-shaped Compose button make its way to Gmail on the web.
The new Compose button is a part of Gmail v2020.05.17.313130477 which is slowly rolling out via the Play Store for all Android devices.