Can BLE U2F security keys be used on Chrome for macOS/Windows for any site supporting U2F USB keys as a second factor?
What sites/apps can I use NFC/BLE U2F keys for on NFC-(and BLE-)supporting Android smartphone?
Now = March 14th, 2017
For now : No. Perhaps in the future if/when Chrome (for Desktop) offer support for FIDO U2F over BLE (now only FIDO U2F over USB is supported).
For now, U2F over BLE support is in beta stage. U2F over NFC is more stable, officially supported by Chrome on Android but not widely adopted. This requires Google authenticator - not for the usual OTP part - (this requirement should disappear in the near future). You should be able to use U2F over NFC on GitHub and Facebook (through web/chrome not through apps).
The devices by Feitian you referenced are the first products of their kind (I already tested them) and you may use them with a beta apk Android application provided by Feitian. This application may offer more compatibility with online services (always through Chrome), but you will still experience issues. Problems are not only related to Feitian parts but to the official Google support too, this should be fixed in the next few months)
To summarize (March, 2017):
- U2F over USB is stable and already adopted by many web services
- U2F over NFC recently became stable, adoption is starting
- U2F over BLE is being finalized (non-official beta support stage, with Google accounts on Android being one example already deployed first adoptions with few issues