Sneak Peek is a free Chrome extension developed by emurphy that falls under the category of Browsers and the subcategory of Add-ons & Tools. This handy tool allows you to view the last message sent in Facebook Messenger or Instagram without marking it as read.

Sneak Peek provides a discreet way of staying informed without compromising your privacy. It's a useful tool for those who value their online interactions and want to maintain a certain level of anonymity. So, if you're looking for a way to stay up to date with your messages without letting others know, give Sneak Peek a try.