Google adds new conversation-related feature to Gmail
The so-called “conversation view” has been added to Gmail for quite a long time, but Google didn't add an on/off toggle along with it. Conversation view allows Gmail users to follow their email replies much easier since there are grouped together.
While the web version of Gmail did allow users to toggle the conversation view off, the mobile app lacked this specific function. The newest update adds the same feature to Gmail on Android and iOS devices.
Keep in mind though that if you have conversation view turned off on the web, it will be turned off on your Android or iOS device as well. In order to disable conversation view just open the Gmail app, tap Settings, scroll down to the “Conversation View” tab and select on/off.