Facebook has become a surprise ally in Google’s efforts to keep its search engine relevant in today’s mobile world. The social giant now allows Google to index its mobile app, which “means that results from Google searches on smartphones will display some content from Facebook’s app, including public profile information,” according to The Wall Street Journal. However, Google will not be able to index content shared via logged-in and private sessions. “Facebook’s cooperation is a sign that Google is making inroads in confronting a big challenge – searching inside apps,” notes WSJ. “Google’s search engine is dominant on the Web, but its computers can’t automatically ‘crawl’ and categorize the information inside apps.”