Most CIOs are eager to find reliable mobile applications that will help keep employees productive, especially during summer months when vacations and nice weather lure workers out of the office. Indeed, the value of smartphones and tablets - whether they are iPhone, iPad, Android or BlackBerry devices - is increasingly being calculated by the applications available on the devices. Realizing that, we've decided to take a look at some of the best mobile apps on all platforms that will satisfy your desire to keep workers productive even during the summer doldrums. Many of these apps are free, others cost less than a dollar and the priciest among them is below $15. So, for little or no investment, you can provide your mobile workers with the tools they need wherever they roam. Once you review this list, chances are you'll want to download a few of these for your own smartphone or tablet as well.