Rattling off a Web search on your phone or tablet is a pretty dead-simple thing to do. Does it really need its own app? That depends. The iPad's out-of-the-box Safari Web browser has a built-in search bar, and you can set its default search engine to Google, Yahoo or Microsoft's Bing. It's just a text box, but it will usually suffice for a quick, heat-of-the-moment query. Other searches, though, may require a little more attention. You might want to target it to a certain category of results.