Not only do they not have a Linux client, but their web client is super limited - it won't give you the passwords that have been shared with you, for example, and you can't register an account through it (on Linux I literally had to install the iOS app on my iPhone to create an account, have my colleague add my account to the team, and then once I could finally log in to the web app, even though it showed me on my team, it wouldn't give me any team passwords).