In China for a short trip, a few notes.
1) Singapore SIM card roaming data works for Facebook and WhatsApp. I bought 1GB 30 days for S$11 with a Starhub Prepaid Card, which is cheaper than the S$20 SingTel 1GB roaming data plan with my SingTel main plan (Combo 2).
2) Tunsafe (Wireguard implementation) does not seem to work.
3) The free one year Seed4Me VPN seems to work with the Taiwan Server, speed is quite slow but good enough for WhatsApp and Facebook.
http://www.speedtest.net/my-result/i/2998887231
Server: SingTel
Download: 1.37Mbps
Upload: 0.44Mbps
The test may not reflect the real speed. At least I can watch 720p YouTube video.
Without VPN it is decent with a 100Mbps broadband and a cheap S$12 Wireless N router.
http://www.speedtest.net/my-result/i/2999184467
41.6Mbps down and 20.1Mbps up.
4) Free Windscribe does not work.
5) Free TunnelBear does not work.
Will try Shadowsocket servers later.