YakYak is similar to Google Hangouts, with a few exceptions. It's a desktop application, so you won't need Chrome to run it. It has different color schemes, including a dark mode. There's also an option for desktop notifications. Other than that, it has all the basics of Google Hangouts, without the need for a browser.
YakYak is a really great option if you're not able to run Google Hangouts on your computer, if your operating system won't support Chrome or you just don't like the browser, or if you're looking for something like Google Hangouts, but with extra features, for you to play around with.
YakYak is good for people who can't run Chrome on their operating systems, or choose not to.