Universal International Power Adapter
I own one of these universal power adapters. I call it the Blue Nugget. Mine has only 2 USB ports instead of the 4 ports on this particular version, but the rest of the features and the overall look are the same.
My experience has been the adapter works like a charm, at least in the EU, the UK, and Singapore. The manufacturer says its compatibility expands to over 150 countries in the EU, the UK, Australia, and Asia. Plus Kenya. Someone asked.
The quad of ports in addition to the standard US outlet come in real handy for charging multiple devices. Especially since one of them is a Type C port for high-speed charging of smartphones and tablets.
For converting between international plugs, the adapter has retractable prongs and slide switches to access them. In addition to making the product more useful, it also allows you to pack the adapter as a perfect cube with no protrusions.