From the customer’s point of view, it is obvious that mobile phones assist you in business a lot, such as, make schedule of working, surf the internet, and keep in touch with their companies.
> "assist you in business a lot, such as,. . " should be "assist you in business by . . "
> Don't shift from "we" to "you"
> "make schedule of working" does not really carry a meaning
> Surfing the internet belongs in the next sentence
Our cellies keep us in constant communication with our families, our friends, and our businesses.