Yes, you can delete a message in a single- or group chat after you have sent it. All you have to do is press and hold the respective message/picture/video/sound and select the Recycle Bin Icon in the navigation bar at the top. Select “Delete from group…” Your group members/chat partner will receive the following notification: “Message removed”. However, it cannot be guaranteed that your chat members didn’t see the message before you deleted it. You can delete a message, after you have sent it, in single- and group chats and broadcast messages.