My next attempt is to get Blinky to work as part of an Android app.  I found some relevant code but my device fell over so I can’t test it yet. Here is the code thus far. 

I found some code on a post but it did not have any configuration settings so I’ve extended it. I’ve created a function that can be called from an Android button handler.

public void GPIO() {
        String command1 = "echo 938 > /sys/class/gpio/export";
        String command2 = "echo out > /sys/class/gpio/gpio938/value/direction";
        String command3 = "echo 1 > /sys/class/gpio/gpio938/value";
        String command4 = "echo 0 > /sys/class/gpio/gpio938/value";
        String command5 = "echo 938 > /sys/class/gpio/unexport";
        TextView textView = (TextView) findViewById(R.id.textView5);

        try {
            Process su = Runtime.getRuntime().exec("su -c " + command1);
            textView.setText(command1);
            su.waitFor();
            su = Runtime.getRuntime().exec("su -c " + command2);
            textView.setText(command2);
            su.waitFor();
            su = Runtime.getRuntime().exec("su -c " + command3);
            textView.setText(command3);
            su.waitFor();
            su = Runtime.getRuntime().exec("su -c " + command4);
            textView.setText(command4);
            su.waitFor();
            wait(1000);
            su = Runtime.getRuntime().exec("su -c " + command5);
            textView.setText(command5);
            su.waitFor();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

I would welcome any comments on the viability of this code, whilst I await an ability to test it, thanks