Only the current version so far — new entries appear as the app ships updates.
Radar Range Equation is a productivity app by Randle Christian Sink with 500+ downloads (about 714 estimated). Released Mar 4, 2015. Install growth, rank history, SDKs and ad networks.
From the store listing: “Enter f (GHz), gain (dB), Pt (kW) and target c/s area and Pmin to find Rmax...”