Nintendo's SmileBASIC for 3DS

This new version was released in Japan and slated for an English release but they postponed it to add a whole pile of new features and have the new release coincide with the English release as well, supposedly also including the new features.

The previous editor was a little painful on the small device, but this new one looks to have a bunch of features that make the New 3DS a viable editing device. More importantly they claim you will be able to share your programs using their cloud service; sharing programs wasn't really viable before (using QR codes).

Most importantly of all you can use every part of the 3DS, including the microphone and all the controls, though I believe the camera can't be used because of Nintendo rules. It's even possible to make networked games for 3DS's in the same room.

Previously there was voice synthesis as well but only in Japan. It has a really fantastic collection of sprites and sounds which is what gets you creating quickly.

Phone controls simply don't compare to Nintendo controls; anything else is somewhat moot beyond that. A pure touchscreen game is always limited in ways that a D-pad and buttons are not.