This is one thing I think could be improved in future versions of B4A, though I'm sure Erel has already thought of it:
Add more "standard" Android views, including the new ones in Android 4.x, so we can build standards-based UI layouts without having to resort to custom classes, libraries, and such.
For example, I would like to be able to add an icon+text button easily, or an action bar, see them in the designer, and set their properties like I can for the existing designer views.
More ambitious wish - let anyone build a view that can be used in the designer. Similar to Visual Basic VBX controls, Delphi VCL components, or Java beans, using a component plug-in architecture.
I think that would make us a lot more productive when creating "standard" Android apps.
Cheers!