From Nookipedia, the Animal Crossing wiki
T&T Mart (コンビニまめつぶ Konbini Mametsubu?, Convenience Store Mametsubu) is the second expansion to Timmy and Tommy's store in Animal Crossing: New Leaf, after being upgraded from Nookling Junction. The upgrade brings increased store hours, a greater selection of items, and the catalog machine, which can be used to order previously held items.
T&T Mart looks similar to Nook 'N' Go in previous Animal Crossing games, with similar glass windows, signage, and automatic doors. The store hours are better than previous games if the Early Bird or Night Owl ordinance is in effect.
The selection of items offered are what follows:
To upgrade from Nookling Junction into T&T Mart, the following prerequisites must first be met:
To upgrade T&T Mart into Super T&T, the following prerequisites must first be met: