QPyCalCount is a sample project for QPython which show how to use QSL4A features.
Please checkout this project and put it on the /sdcard/qpython/projects.
You need to install qsl4ahelper-qpython2/qsl4ahelper-qpython with QPYPI before running it.
pip install qsl4ahelper-qpython2
Then you can run it from QPython's Quick Start.
Author: Hariharan Srinath
It's based on the FullScreenWrapper2: An Python SL4A GUI framework for Android
It could be ported to QPython3 easily. You can try to port qsl4ahelper-qpython2 to qpython3 first. That will be great if you are interested in helping this.