So, you are going to another city. We read literature and mapped out routes. In order not to walk with a book and not ask passers-by where the next attraction is, I suggest using a bunch of Google Map and a free program for iPhone My Maps. The idea is to create an account in Google. Create your own map on your computer in the Googe Map service. On this map you can put the necessary places to visit, you can with a description and photos. It is possible to work with the map as a whole group, or even open access for editing to everyone. By this principle, by the way, WikiMapia is edited. You can also use someone else's card, though only on a specific link. There is no search for personal cards in the service. So you can open the ability to edit the map for everyone. If you have the time and patience, then you should get a visual guide. But the fact is that you can view this map from a mobile device operating under iOS, but you cannot add anything to the map. Here you will need the My Maps program, which is installed on iPhone and loads the maps Google Map. It describes in more detail how the program works and how to load your routes to iPhone. In addition, this program has the ability to add new tags on the fly. They really don't sync with the Googe Map service, but at least something. Moreover, the program is absolutely free.
As an example, here's my homemade travel guide to Rome. Here is an audio guide to Rome in mp3 format, and a map of the city with labels. The tag number corresponds to the audio recording number. Rome Map Rome Audio Guide