Is it expensive?

iphone-track.com is the cheapest automatic tracking software you can find at less than $5/Month when you purchase a full year.

What do I have to download to the device or my computer?

No downloads, nothing to install, only need Apple Id and Password for device

Do I need to have physical access to the iPhone/iPad/Mac, and do I need to jailbreak the iPhone?

Access to the physical device not required, no jailbreak required

Does it work on Android?

Works only on iOS Devices and Mac OSX

Is there a way I can look at the location of the iPhone in real-time to know the current location?

You can perform Real-Time Tracking on an interactive map.

Do I have to be watching to be able to know location later?

You can Perform Scheduled Tracking and review the data later.

What else can I do?

Review raw historical results over a time period on an interactive map.
Review processed historical results to show important points over a time period on an interactive map.
Review processed data that shows just the locations visited as well as the durations on an interactive map.
Review processed data that shows a list of locations visited as well as the durations.

What else do you have planned?

View Contacts
View SMS/iMessage contents
View calls and durations
View all calls and texts
Organized as a single list
Organized based on Contact
Ability to select contacts to include in a single list
Ability to filter based on time
Ability to also include processed location data

Will the additional features be at an additional cost?

As features are added, existing customers will not have to pay anything extra as long as they stay paid customers.