This is the place where Stones fans can advertise anything for sale, wanted, trade or whatever, from fan to fan. Advertisements are for free. To see the old ads go here.
I found the ubiquitous Google Maps to be excellent. I downloaded the area I need (the whole of England basically) for offline use, and it has very rarely let me down and I've been travelling all around England and Wales for nearly a year.
For getting around major cities, City Mapper app is really good. It gives options of trains buses, taxis, cycling and walking etc. and how long each will take.
It only covers London, Birmingham and Manchester in the UK.