I bought the Belkin Boost Up. It's pricey at $60USD but I felt if Apple endorses it, it would be high quality and reliable.
It works well, comes with the power adapter, and will support 7.5W charging, keep that in mind. The cheaper ones are 5W max and you supply your own wall adapter. It will surely charge at a a slower rate than your Apple-supplied 5V adapter due to the inductive power loss.
The Boost Up is a bit big, looking like a saucer spaceship. If you have a non-Plus phone, it seems bigger than it needs to be.
I also ordered a cheapo Choetech Circle Qi at $14 from Amazon. Will try that and compare. But it won't do 7.5W fast charging and although it comes with the cord, you supply your own adapter.