Social Media Marketing

Such as apps.. ? I know Twitter has that mobile device thing where you put your phone number and receive updates. But I want a way to easily access onto Twitter on my phone. Are there only certain types of phones that can do that?

Because i text the code to the number and i dont get any reply and on twitter it says that twitter is not currently SMSing from that number. How to i get it to have my number so that i can text my tweets?

I don't want to receive a notification every time someone writes on my wall or sends me a message. How do I stop this? I went to my facebook settings for notifications, but that only tells me about notifications by email, I couldn't find where I adjust notifications on my mobile device.