To hide an application from being displayed on the website, click on "My WhatPulse", then go to "Applications". You will then see a list of applications that have been sent to the website from your client. By default, your application statistics are publicly viewable.
To hide an application from public view, click on the eye icon on the far right column of the list. The application will then be shown in strikethrough, and the eye icon will be crossed out. Click the eye to unhide the application again.
If you are looking to hide all applications, you can do so in your Privacy settings in My WhatPulse.