I have a handful of the 2-prong version, which I've purchased on-island for a few Euros each.
What you probably don't need, at least for any portable electronic device manufactured in this century, is a transformer. To expand on what Tim said, if the power supply for your iDevices and laptop are labeled Input 100-240V, 50-60-Hz then you should be OK without a transformer.
Must have ben a bad wiring problem in the villa. I've used iPads (and iPhones and Macs) all over the world on 240v with the standard Apple plug and an adaptor.