Can I obtain an EAD?

You can not work on a visitor visa. When you arrive at the border, and you give the customs officer a hint that you're going to be working, they will send you back to your country immediately. Also you have no fourth amendment rights against the government looking at your phone, which they sometimes do when you enter the country. If there is any evidence on your phone that you plan to work, they will also send you home immediately and revoke your visa.