The brand-new Efteling app went online a few hours ago. You can find it
here for Android, though it doesn't seem to be available for iOS yet.
Just downloaded and had a play about with it. Although it's a little short on features, the actual map element (which is combined with queue times) is a really high quality product, probably the best of any theme park app.
You can select different layers (attractions, food & drinks, toilets for example) to control how you want the map to look, and each little 'bubble' for an attraction or restaurant will pop up with all the details such as waiting time, height requirement and even whether there is Halal food available or not.
There's also some sort of day planner thing, which works really well and lets you create a 'checklist' of must-visit attractions, as well as telling you the weather forecast for the day and welcoming you when you arrive at the park. It's also all in English, which is great. Some screenshots below.
If you like Efteling, I advise that you download this app as it's really great! We'll see tomorrow if you can view queuetimes from outside the park, fingers crossed.