OL3-ext: Hover interaction
is an interaction to do something when hovering a feature.
The cursor options lets you spécify the cursor when hovering (or use setCursor())
The featureFilter and layerFilter lets you specify which features / layers are concerned.
You can use handleEvent options of the ol.interaction.Interaction to extend the interaction.
The interaction fires hover, enter, leave events
you can use to get the feature/layer that is hovering and do some stuff (show a popup, display information, change cursor, ...).