BERKELEY -- Unsure which presidential candidate's platform would be better for your household's or neighborhood's financial bottom line? Don't worry: There's an app for that. Politify.com lets a user input his or her salary, other income, age, tax status and other data, and produces an estimate of how much the user would gain or lose under President Barack Obama's and Mitt Romney's respective tax and budget plans. But cofounder Nikita Bier, 23, of Berkeley, said Friday that while the site's earlier version was little more than a tax calculator, the version launched Aug. 23 also uses "a complex merger of...