Your app rating is great and has been since launch it's the lack of US based reviews that's the issue.
28 reviews from users with US play store accounts in the last two weeks, almost all of the names are Indian but well give them the benefit of the doubt and assume they are real U.S based installs and not users from India using U.S based accounts.
1 IOS review and rating in the last two weeks. Not exactly going viral.
If only you could convert some of those 750,00 bot views into installs ...