[APP] My 5.0.1 watch face doesn't install on some devices topic

I've been developing a sample analog watch face that uses 24 hours scale, on request of a friend. It works well for me, as well as for some other people. The problem is that on the friends Samsung device it doesn't install: he clicks install button, and nothing happens. Also another Samsung user reported a similar issue: the app installs, but stays invisible on the apps list, and no new watch face appears. I can not reproduce the situation in any way. It works well for me every time, as fell from apk file, as from the alpha channel on the Play Store. Could you guys give it a try? Download form box or join the group and download alpha from the Play Store. I'll really appreciate any help.