The app developed by Tiger Lab apps but still have many bugs that need to fix since this is the prototype application. It is just a evidence that Android could play the Nintendo DS game. So, of course we need more time to get the stable nintendo DS emulator for Android or might be Nintendo follow the Sony Ericsson method to launch Android phone with special console for Nintendo DS.
The NDS emulator is very early prototype version and for demo only. It is very very slow so you shall not expect to play NDS game with this emulator. It is used to DEMO that NDS game can be played on android phone. It is shown that NDS WILL be played some days on android phone, maybe 2012 or later.
However developer will concentrate to some issue such as;
1. More powerful phones
2. Dynarec CPU simulation
3. GPU simualtion improvement for speed greatly.
4. Hareware render (eg, OpenGL ES)
5. FPU. Since NDS need lots of float calculation. FPU can improvement performance greatly. Later ARM will have FPU in feature.
The NDS emulator only for high-end Android phone. If you do not have a high-end phone, do not try NDS game. Even if you have a high-end phone, just try some small games(none 3D) but it is also quite slow.
So how to play as demo the NDS game on Android phone
1. Put your nds ROM files to /roms/nds folder in sdcard.
Note. zip nds rom is not supported, you shall extract them to be *.nds files
2. Launch TigerNDS which will load those NDS roms in game list
3. Select one game and play
Since the NDS emulator is just DEMO and speed is very slow even on high-end phones. You shall not expect to play nds game with the emulator. Just wait for a moments to give the developer finish their task like we said above to bring the app quite enough for us to play NDS game on Android phone.
Technicaly phones with 800Mhz+ should be able to run NDS emulation. Practically it will take lots of time developing very fast/efficent app, however would love to see one. At this very moment you could enjoy NES/SNES/GBA/PSX emulation, though controls are not good for fighting games but for RPGs (FFVII ^_^) are good enough.