You're breathing a sigh of relief because you've filed your taxes for 2011. But what if your taxes reflected the true cost of the federal government's annual expenditures? How much more would you have to pay? To find out how much that true cost might be, go to Debt Bomb, a new 99-cent app launched last week for your iPhone, iPod Touch, or iPad. You key in your age, your income, your expected income over the next few years, and the software will give you your household's average tax bill to cover Uncle Sam's annual spending. Then, through the app,...