Zeplin has desktop apps for only Mac & Windows at the moment — we're excited about working on a dedicated Linux app in the near future! 🙌
Meanwhile, you can use Zeplin on Linux distributions like Ubuntu or Fedora on our Web app: https://app.zeplin.io
If you're a developer, when your designer uploads the designs to Zeplin and invites you to the project, you'll be able to access all the details through the Web app. It offers the same functionality as the desktop apps, except for uploading designs.