Also depending on the carrier you have, you may be able to get an in-home cell antenna. Verizon has a Network Extender, AT&T has a Cell or whatever it's called. Basically runs off your home high-speed internet to give you a mini cell tower in your house. I have one at my house, works fine (though if someone is streaming heavy HD movies on the same router it's hooked through, it's a little delayed on the voices). The Wilson ones are good too, and would likely work, but are a) more expensive for a complete solution, and b) a LOT more expensive if you want whole house coverage. But the Wilson's are also not carrier-dependent. A Verizon extender will only work with Verizon phones, etc.
As far as anything else, there's not really anything that you're going to be able to download to your phone to increase your signal over what you have. Different ways to display the signal, sure, but nothing to boost it by itself.
