Thank you for the further information. The version of Android you are using does not meet the minimum requirements for the Xibo for Android Player. This likely explains the issue you are having.
Xibo for Android requires Android 4.4 or higher, I would recommend updating your Android device or looking for an alternative hardware solution that meets the minimum requirements. For reference, I have included a link below to our Recommended Android Hardware Guide:
On a side note, I would also recommend upgrading your CMS to a newer version, ideally the Latest version as you will find many fixes and features have been added since 1.7.9. This is of course your choice and if you are happy with your setup then it is not necessary.
Many Thanks.