Under certain circumstances, you will have to stop your Azure AppService / Azure WebApp before deployment as it may lock DLL-files (and thus prevent a successful deployment).
This extension has two tasks, one is for stopping and the other one is for starting an Azure AppService / Azure WebSite as a part of a VSTS build.
The tasks has been tested with a hosted instance of VSTS in combination with Azure AppServices.
How to use
Configuration of the build steps is done similar to the standard Azure PowerShell build step, i.e. you will have to connect your subscription to VSTS and then select your subscription from a list. You will also have to specify the name of the AppService to stop / start.
Source code and technical information: https://github.com/rbengtsson/appservices-start-stop