How to boost download speeds on mobile?

I was wondering whether there are any mechanisms available to boost the download speeds on mobile phones. There's software like 'Connectify Dispatch Ready To Combine Your Internet Connections' that combines all your accessible Internet connections into one solid connection and increase the download speeds. I haven't seen anything similar on Android or iOS yet.

If you know any such app that lets you join multiple networks (multiple WiFi + 3G) to form a thick connection that combines the speeds of all these networks, please let me know.