Dear bro , the problem is not just your signed apk , on typing "yandex shell" in search option shows nothing ... It says "unfortunately,there are no results for your search"....!!! Now this is the point of concern...
More clarification: I don't see Yandex.Shell in search result either, but I do see it in My Apps of Yandex Store if I installed Yandex.Shell from Yandex site.
Just follow post #114
Sent from my GT-N7000