Two days ago, using the Satellite AR app, I noticed that Inmarsat 3F2 at 15W is well above my horizon, probably enough to be received. Yesterday I temporarily put a satellite dish on my roof to try and aim at it. I had no success but I did easily receive the one at 54W. Using JAERO, I was able to decode an AERO channel and get some aircraft messages. When I looked up one of the registration numbers, it turned out to be from a plane flying over Algeria.
Here is an Inmarsat page with coverage maps for their satellites: http://www.inmarsat.com/about-us/our-satellites/our-coverage/