Your yaps and archive are located on the same tab, and you can access your archive from your yaps tab by clicking the yaps icon at the bottom of the screen to switch between inboxes.
If you have not archived any yaps, your screen will appear blank - which leads some users to believe their yaps have disappeared. Click the yaps icon to get back to your chats.
If your chats are missing from your Yaps Tab, please contact support@yapster.info with a screenshot of this.