The
Dual XGPS-150 Bluetooth GPS works with Locus Pro, and
without needing a "helper app" as Dual's instructions for Android says. However, when running with this external GPS, there is no accuracy circle, no "line to GPS" and no "course bearing line". These features are very useful for my application, and the external GPS is preferable because I am running Locus Pro on a tablet in an aircraft cockpit. The Dual can be put on the glare shield above the instrument panel and always gives excellent position with many satellites.
edit:Reposting this in case it slipped by without seeing it :-)