You can refer the attached sample of using FusionWidgets in an Android native application.
Similarly, you can update this application to render a Gantt chart instead of Angular Gauge.
Also, the PDF may prove to be helpful.
FusionWidget+Android Sample - https://www.dropbox.com/s/tisri8pefjmpei2/FusionWidgets.zip
PDF- How to use FusionCharts with Android Mobile Applications- https://www.dropbox.com/s/pz9772tvobxooel/Android%20Native_How%20to%20use.pdf