Wondering whether it's worth your company's time developing your small business mobile apps? Wonder no more. A survey by AT&T and the Small Business & Entrepreneurship Council has found that mobile technologies save small businesses $67.5 billion a year. Just under half of the savings comes from the use smartphones, the survey found, saving small businesses 1.24 billion hours a year, for $32.3 billion in annual savings. Next comes tablets, which account for 754.2 million hours and $19.6 billion saved a year. And mobile apps lead to 599.5 million hours and $15.6 billion a year saved. The survey was conducted with with 1,042 small businesses from 48 states and the District of Columbia from March 26-31, 2014. More than half of all small businesses now use mobile apps, and it leads to significant productivity gains, the report found. Some 91 percent of small businesses say mobile apps save them time, and two-thirds say it saves them money. How much money? A majority of businesses say they're saving $6,000 a year thanks to mobile use.