While DragQueen was the best, it is apparently no longer available for ios devices. Although it appears in google searches (DragQueen Anchor Alarm) in the itunes store, it does not appear when actually searching in the itunes store or in the app store. Too bad.
It's available - But the note says it hasn't been updated for IOS 11, so it's not shown as available when searching from "current" devices. Dust off your iPAD 2... ?