There are a number of free online pre-flight planning tools available to assist pilots in safely and easily planning their Visual Flight Rules (VFR) flights in and around busy airspace and to check NOTAMS.
NATS has awarded its Safety Compliance Mark to SkyDemon Light. The mark indicates that the product complies with functionality set out by NATS to enhance flight safety. It is available online at http://www.skydemonlight.com/ as well as being downloadable as an app for phones and tablets.
Other electronic flight planning tools are available in the form of paid apps and online services that add more functionality such as filing flight plans and in flight weather.