Screen Sieve
… lets you search the contents of the currently active window at any time. It highlights all occurrences of characters, words and phrases as you type, without requiring modifications to applications. Putting Mac OS X' built-in support for Accessibility to good use, Screen Sieve works with any application that supports the Accessibility APIs.
Best Screen Resolution to Design Websites
There's no one best screen size to design for. Websites should transform responsively and fast at all screen resolutions on different browsers and platforms. Accessible. Mobile-friendly. Design for your audience, first. Design from 360x640 through 1920x1080.