WalkJogRun is excellent. You just log onto the app and it gives you loads of routes that you choose depending on distance you wish to run. I have used it all round the world and it has never let me down. For example they have nearly 100 routes available from 1 to 44 miles from my work.
Hi all I am running the marathon too. I have just got back from Valencia last night, and the weather was HOT ( 28 + every day ). Bit worried about how it will be on the big day. It is a lovely city and there were posters up already about the marathon.