Here is the gateway 3ds frequently asked question with Gateway Ultra :
Before you read this FAQ list , make sure you get this gateway 3ds which is from the official site : http://www.usar4.com/gateway-3ds-gateway-3ds-flashcart-play-3ds-games-on-3ds-xl-3ds-p-8.html
Q : How do you get original DS games to work on 3DS with gateway 3ds ?
A : The Gateway product comes with two flashcarts, one for 3DS games (known as Red Gateway because the label is red) and the other for DS Games (The Blue Gateway). If you want to play DS games just put the games in the Blue flashcart’s microsd.
Q : How to you add themes to your 3Ds menu?
A : After you have a emunand you can update it to the latest version of firmware (currently 9.5) and then you can enter eShop and buy games/themes as normal.
Q : Can i make shortcuts to the games on the menu rather than having to open the gateway list?
A : You can install the game in .CIA format, then it is kind of like some game you got at eShop, it gets installed to the emunand in the SD card that is inside the 3DS and acts like a new software in the 3DS menu. Pirated and custom themes are also available as CIA downloads.
Q : Can i play online with gateway 3ds ? How do you get an online game to work for example Mario Kart 7 or Pokemon?
A : Yes. You need the game to be patched with online-enabled headers. You can download games already patched with public headers (ban bait) or patch them yourself using some private header you own. You can also play online with .CIA eShop-like roms.
Q : Does Streetpass work and internet things like the eshop work?
A : Yes, with the emunand you can enter eshop, download demos, buy games, etc. Streetpass and all.