Thank you so much for trying the app and I am sorry that it has not worked the first time. What version of Moodle are you running?
For troubleshooting it is worth checking that the web services are working correctly.
First enter your web address in this format in your browser.
This should return a token or a message to let you know that the webservices are not enabled correctly.
Secondly ensure that you're entering your website without "https" as this is not yet supported and try it with and without the slash at the end of the moodle site address. The app will also not function if there is a custom login script.
If that works I would suggest logging into our demo server using the details that are included with the app to see if the app is behaving correctly on your device.
One last question, what plugins are you using with moodle?
That should get things started.