Yesterday, Google announced that it would be discontinuing Chrome Apps in mid-2017. This means that popular Chrome-based REST clients like Insomnia (2.0), Postman, Advanced REST Client, and DHC will become unavailable.
Luckily, there are many non-Chrome alternatives to choose from so you can quickly get on with your work. Here are some of the most popular alternatives.
Insomnia 3.0 (Mac, Windows, and Linux)
Insomnia (what you're looking at), is a well-designed cross-platform REST client. It's free, easy to use, and offers advanced features like cookie management, global environments, and code snippet generation.
Postman Desktop (Mac and Windows)
Postman is probably the most popular REST client. It offers advanced features like automated API testing, team collaboration (paid), and even documentation generation. It's vast feature list makes it a bit harder to learn than other clients, but it's very powerful once you get up and running.
Update Aug 22, 2016: Postman now has a blog post on the Chrome App shutdown as well.
Paw (Mac) $
Paw is a fully native and well-designed desktop app for Mac. It offers many of the same features as Postman, and is easy to use due to the teams' focus on design. Paw comes in at a $50 (USD) price tag but offers a 30 day free trial as well as a 30% discount for students.
HTTPie (Command Line)
HTTPie is a very intuitive command line tool that makes interacting with HTTP APIs a joy. If you aren't looking for a visual application, I definitely recommend checking it out.