KnowTrail is an amazing application for iPhone that lets you explore your surroundings by fetching information about places, events and other items of interest that are located near you!
KnowTrail has two modes, Online Mode and Offline Mode. In Online Mode content is fetched from Wikipedia depending on your location. You get a list of all related items and you can select one to read everything that has been written in Wikipedia about it.
The amazing thing with relying on Wikipedia is that apart from places and physical objects you can also read about historical events, organisations and anything else that appears to have a connection to the place you currently are. Imagine that you happen to hike on a specific hill and upon checking KnowTrail you discover that a certain battle some hundred years ago took place right where you are!
After you select an item in the Nearby tab you are transferred to the article page. On the right hand corner there is a plus button which adds the current article to the reading list. You can see all your items in the reading list by selecting the Reading List tab.
KnowTrail also features Offline Mode, a mode which allows you to download information about the whole area around you (most of the times covering an entire city) and have the same experience as when you are online.
In order to use Offline Mode you first have to download the information by navigating to Settings and then to Offline Data. Then you can press on the Download Area Information and check the progress on the top of the screen. When the process is finished you will see the map filled with markings for all the entries that were saved. You can click on any of them and maybe add them to Reading List for later reading.
After downloading all the data you can now activate Offline Mode in the Settings tab. Then you just switch back to the Nearby tab and you should see related Wikipedia entries even when you are not online!