There is no mention of SMS and Call Filter on that Eset webpage. It appears that the apk which you refer to is no different than the one that is obtained from Google Play. So if I want SMS and Call filtering I am better of getting one of those other Apps.
Why can't ESET sell the .apk file outside of Play Store with updates offered via email reminders? Also there are other Apps available for blocking calls how do they get past Google's policy?