...and what can it do for you? In a nutshell:
...and a lot more. But you'd have to explore the site to find out! Essentially,
Flightwise is an aviation solutions website. It links pilots, FBOs,
and Aviation enthusiasts alike - together, online, and services both sides of the
coin.

Flightwise is a web site for pilots of all kinds. It allows them to
obtain detailed information on airports, their runways, frequencies and services
available, navaids, airways, intersections, and other parts of the US National Airspace
System. In addition to providing this information, it also allows users to
create and store frequently used flight plans, and allows you to file them with
the FAA automatically.
FBOs and other on- or near-field services can benefit from Flightwise in
a number of ways. First and foremost, by listing their FBO with the site,
they can advertise their services and attract valuable traffic to their facilities.
In addition, FBOs (as well as pilots) can track flights that are on an IFR flight
plan; the Airport Summary feature allows FBOs to see which flights are due
inbound, when they will arrive, what type of aircraft they are, and where it is
currently located at any given moment - a great help for FBO line crews and staff.
For Developers
Flightwise provides an excellent, low-cost Flight Tracking API, PlaneXML! Access near-real time flight
data as well as historical flight data, and integrate it with your own custom application.
Flight Tracking