DragMath sounds very promising! Congratulations! I have some suggestions:
(1) The possibility of a custom tab where only a restricted subset of functions and operators are shown and, also, the possibility to show *only* this tab (for instance, secondary school students don't need to worry about calculus operators).
(2) In portuguese, "sin" is "sen', "tan" is "tg",etc. It would be nice if these functions could be changed as the language is changed inside DragMath!
Thanks in advance, Humberto.