Black Gold

Price: Free

For several reasons you should track oil and energy prices: their general effect on the economy, a loose relationship to ethanol and corn prices, and the apparent lack of any relationship between natural gas and fertilizer. From the Dallas-based company, Breitling Oil and Gas, this free app offers daily West Texas Intermedi- ate (WTI) crude prices and monthly, quarterly, one-year and five-year charts; also gasoline, gold, natural gas, and heat- ing oil. A 99ยข upgrade gives better charts and state-level gasoline prices (which include E-85).