Thanks for the suggestions @Jessey, @GaryB and @newforest. That last one looks very detailed! Mine is proving quite accurate for the '5 minute' interval cloud tracking, which only goes up to 45 minutes ahead I think. I can set it for longer intervals which goes further into the future but isn't as accurate. The 5 minute one is quite handy if you want to know whether the rain is going to stop/start in the next half hour though. I'll download the others if they're available for android and free and do a bit of a compare.