Did you know that the iOS Messages app allows you to easily browse through the photos and videos in your iMessage or text message conversations? When you tap on a photo to view it in full-screen mode, you can swipe back and forth through all of the photos in the current conversation, much like you would in the Photos app. In addition, tapping on the button in the bottom right corner while viewing an item will bring up a list of all of the media in the current conversation, with the current item highlighted; you can tap on any item to go directly to that entry, and then continue swiping left and right from there.
Keep in mind that Messages only displays the last 50 messages, but all of your older messages remain stored on your device unless you’ve manually erased them; you can access these previous entries by scrolling up to the very top of a conversation and tapping Load Earlier Messages. Once loaded, any older photos and videos in the conversation will also be included in the media listing and browsing views.