A new kind of flashcart mode released today---SuperCard DSTWO PLUS 4 in 1 Flashcart. It's a big upgrade on DS flashcart DSTWO which can play NDS/GBA games with its unique CPU.

Let's see its super Fetures about the new 4in1 DSTWO PLUS:

3DS game support.
It's the only flashcart in the world that supports 3DS, DS, GBA and SNES.
DSTWO PLUS --- One flashcart for all.

POWERFUL HARDWARE
DSTWO PLUS features a powerful onboard CPU along with 32MB of RAM, which
allows for GBA and SNES support, along with other amazing real-time features
you won't want to miss. And they're all accessible during normal gameplay.
Compared to DSTWO, DSTWO PLUS has 4x the Flash and 2x the CPLD power.
It all began with the DSTWO, but PLUS is to go even further beyond.
*PLUS will support new 3DS versions through an upgradable firmware feature.

Detailes about the function:

1 / Gateway Plugin Emulation. (3DS game support)
Using the Gateway plugin, we can emulate a Gateway flashcart. Why have two cards, when only ONE is enough? No region limitations, any game on any 3DS. And just like always, it's really easy to use. How to use

2 / DS Games support (DSTWO EOS)
The No.1 DS flash cart, the perfect DS gameplay system in the world. Our DSTWO EOS system comes with a lot of powerful functions: Real-time Save, Free Cheat, Real-Time Game Guide, Slow Motion. 32MB of RAM also fixes a lot of TF lag problems, which could corrupt your games in the past. How to use

3 / GBA Game support (TempGBA)
TempGBA is based on the official GBA emulator, it's the best and the only one that allows people to play GBA games on 3DS. And it’s also the only one that runs Golden Sun perfectly. How to use

4 / SNES Game support (CatSFC)
A perfect SNES emulator only possible with our powerful hardware, this makes DSTWO PLUS is the only card in the world that can play SNES games perfectly on 3DS. How to use