We present input techniques for smartphones using a sty-
lus based on magnetism. Our techniques use a magnet
attached on a stylus and a three-axis internal magnetic
sensor in a smartphone. Using our techniques, users can
input into a smartphone using a stylus on the surface on
which the smartphone is placed. This enables users to em-
ploy a wider surface than the display of the smartphone
for input. In addition, our techniques require no additional
sensors on the smartphone. In this paper, we present two
input techniques: nonelectric and electric ones. In addition,
we describe our stylus for use with each technique and a
coordinates-estimation algorithm we implemented. We also
describe two applications: a digit recognizer and a paint
application.