POP (Prototyping on Paper) - POP helps you make interactive prototype with ease. If you can draw, you can design apps.
WP Remote - WP Remote provides a single place to monitor and update all of your WordPress sites.
Balsamiq - Balsamiq. Rapid, effective and fun wireframing software.
Siterack - Automated website maintenance for WordPress.
Marvel - Turn sketches, mockups and designs into web, iPhone, iOS, Android and Apple Watch app prototypes.
ManageWP - ManageWP is a service for bloggers, site owners and web based companies helping them manage multiple WordPress sites from one dashboard.