Blur is free to use. It doesn't need to be set up or installed, because comes pre-installed on specific Motorola phones, like the Devour (but you will need to tell it your account info for Facebook, etc.).
If your phone doesn't already have Blur, you can't add it; it's not an app you can download.
Blur is not the only way to have your phone keep you up to date on your social networks. Most smart phones have widgets and apps for Facebook, Twitter, etc.. Also, Verizon has just introduced phones called Kin which are designed from the ground up for social networking and may be a good alternate to Blur phones.
If your phone doesn't already have Blur, you can't add it; it's not an app you can download.
Blur is not the only way to have your phone keep you up to date on your social networks. Most smart phones have widgets and apps for Facebook, Twitter, etc.. Also, Verizon has just introduced phones called Kin which are designed from the ground up for social networking and may be a good alternate to Blur phones.