UML online tool

Hi there,

I need a UML online tool for designing my class diagrams and use case diagrams. I had a look at what VisualParadigm provides for UML. All I need is class+use case diagramming (+ UML2 compliance) for me and a trainee.
Is this UML online offer the most appropriated version? Or is there another VisualParadigm product matching my needs?

Thanks for your help,