RapidDeploy is described as 'Powerful application release and deployment automation tool. Built for DevOps teams and enterprise continuous delivery, RapidDeploy delivers consistent high volume deployments so your teams can focus on developing' and is an app. There are more than 10 alternatives to RapidDeploy for a variety of platforms, including Windows, Linux, Web-based, Self-Hosted and Mac apps. The best RapidDeploy alternative is Octopus Deploy. It's not free, so if you're looking for a free alternative, you could try GoCD or BuildMaster. Other great apps like RapidDeploy are PDQ Deploy, Bamboo Continuous Integration, Automic Release Automation and DeployPlace.
Octopus Deploy is primarily for Windows applications.