Twitter said it is now tracking what other apps its users have installed on their mobile devices so it can tailor content and ads to them better. Twitter said Wednesday that users will receive a notification when the setting is turned on and can opt out using settings on their phones. On iPhones, this setting is called “limit ad tracking.” Besides advertising, Twitter said that knowing what apps people have downloaded can improve its suggestions on what accounts to follow and add relevant content to their feeds that isn’t advertising. A recent Pew Research Center poll found that about 80 percent of Americans who use social networking sites are concerned about third parties, such as advertisers, accessing data that they share on the sites. The stock market eked out another record close on Wednesday ahead of the Thanksgiving holiday as investors assessed the latest reports on the economy and some corporate earnings. Orders for long-lasting manufactured goods rose in October, but a key category that tracks business investment plans declined sharply for a second straight month. Consumers spent modestly more in October, a slight improvement after no gain at all in the previous month. “This seems to be a classic holiday plateau,” said Kristina Hooper, head of U.S.