The documentation at https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/components_config_for_flow_screens.htm says that if a Lightning Component implements lightning:availableForFlowScreens it should be visible in the Cloud Flow Designer, but it isn't.

This is the component:

<aura:component description="FlowCmp1" implements="lightning:availableForFlowScreens" access="global">

    Oh haiii

    <lightning:button onclick="{!c.doTheThing}"/>

</aura:component>

({
    doTheThing : function(component){
        var navigate = component.get("v.navigateFlow");
        navigate("NEXT");
    }
})

Pls help!