Do I have to actually be in the city I select to use the app?
No, you do not need to be there! With Remote Walk, you walk anywhere — in other words, your normal walking routes. You will have a virtual experience like you are in the city you selected, including passing the landmarks on the way.
When I turn on my real walk, will it possibly stray off the virtual route?
Turns in real life have no effect on your heading on the virtual route. The virtual route itself is fixed. You can walk in any direction you want in real life. The app only measures the distance you travel and then advanced along that preset virtual route. So just walk anywhere and however you like!
Can I have it use my steps instead of GPS?
By default the app uses GPS to track your distance. Due to the nature of the iPhone, using GPS has the benefit to allow the app to tell you as you pass things even when the app is in the background, and your phone screen is dark (which is mostly the case while you are walking).
You can go to More->Settings and change to use steps. Some like this experience a lot also. It will keep track of your position on the virtual route in this mode and allow you to see landmarks still. The difference from using GPS though is that with steps you will will not hear real time updates of what you pass. You must go back into the app to see.
I started the route, but my person icon just stays in the same place on the map. Why?
Usually this is because you are not actually moving in real life! If you want to progress through the route without moving, you can go to the More tab -> Settings and set fixed speed. This will cause the app to always assume you are traveling at 3.5 mph without actually checking your movement.
Can I use the app on a treadmill?
The default mode of the app is to use GPS to track your distance, so you have to actually travel in real life for the app to work. Therefore on a treadmill you will not progress through the virtual route.
If you go to the More tab and select settings and change the mode to either steps or fixed rate, it will work on a treadmill (although in the case of steps, you will actually need to have the phone on your body so it registers the steps).