No, AT&T is separate
Yes.
No it does not have wifi calling because that aplication is developed for tmobile phones.
Singular cell phones are not a common or widely recognized brand. It's possible that you may have meant to refer to Singular Wireless, which was a former telecommunications company that is now part of AT&T. You can find AT&T phones in AT&T stores or authorized retailers.
T-mobile offers this service on-line, not sure as of yet if it is available in store. Probably not.
I have added a link below to a online pre owned cell phone store that has T-Mobile phones. Hope this helps.
The phones that are available for the no contract prepaid plan with T-mobile are Concord, Nokia X2, T Mobile 665, LG Optimus, My Touch, Blackberry Curve, and just about any Samsung phone. All T-mobile phones are also available to use prepaid.
How do i get a tmobile account on a at&t phone?
http://www.t-mobile.com/shop/phones/?shape=smp TMobile offers a variety of free smart phones on their Web site.
With their prepaid plans Tmobile has Samsung phones such as the Galaxy and the Exhibit. They also feature LG phones such as the Optimus. Additionally they have a their own model called the Sidekick.
There are many things one can to on the T-Mobile website. One can purchase phones, accessories, internet devices, ask for services, and can set their plan for their phones.
Tmobile does have prepaid phones without the contact. You can get unlimited text, unlimited data, and 100+ minutes to talk for about 30$. The Tmobile website has more details.
Yes, amazon sells t-mobile phones. The amazon website also sells accessories you can buy with your phone; if you decide to buy a phone from the amazon website.