Are you referring to The Apple of Idun? Also known as Song of Lutie o_o? If so, in skill.c it shows it increases your HP perfectly fine;
case BA_APPLEIDUN:val1 = 5+2*skill_lv+st->vit/10; // MaxHP percent increase if(sd) val1 += pc->checkskill(sd,BA_MUSICALLESSON);break;
@msyterious the skill is working but it say on the description max hp +25% but when i use it only gives 12% of my max hp...and in other players that inside the apple of iduns gives 13%....
all i want is to increase the effect of the apple iduns i already try to increase the value but nothing change...