Its no real problem, v1.6.7 works fine for me.Hello,
The Google Play supports rolling updates to partial of users. I always use this feature in case there is any big issue in the latest release and I can fix it soon without impact all users.
So some users may see 1.6.7, the others may see 1.6.8.
FYI: when I tried downloading the one from your official website, the APK that downloaded was a REALLY old version. I simply followed the links in the OP.