Smartphone and tablet apps have revolutionized the hobby of planespotting. Though I use an iPhone and an iPad, many of these are also available for other platforms. Here's a summary of what I use and how I use them.
Flight tracking apps and websites have become a very useful tool for planespotting. They make identification of aircraft very simple, even for those that may setill be many miles away. For most of the last year, I solely used FlightRadar24 . It is a very full-featured app that provides an all-in-one flight tracking solution. It provides both standard tracking on a map and augmented reality (AR) tracking where the device's camera is pointed at a plane and a bubble identifies information about that flight (flight number, type, registration, etc.). There is a very slick user interface and the ability to filter by airline, type, speed or altitude. However the notifications (available through an in-app purchase in iOS) currently leave a bit to be desired. Recently, I have also begun using the Planefinder app for my iPhone. Planefinder has superior notifications ability and the potential for extremely thorough flight information. The user interface is a bit less refined, and the app is far more dependent on things such as the open-ended entry of codes, as opposed to FlightRadar24's drop-down lists of names. They also use 4 separate apps, each available at additional cost, to provide the same map-tracking and AR capabilities as FlightRadar24 on both iPhone and iPad. I also use the venerable Flightaware app on occasion. It is the best way that I have found to get information on a flight that has yet to fly or has already landed. Both Planefinder and FlightRadar24 are only available while the plane's transponder is active. However, I have found that there are many holes in Flightaware, especially in the app. For example, if I search a particular airplane's registration, I will get plenty of information, but not the airline or flight number.
Personally, I find the ability to have a text listing of arrivals and departures to be very useful. It is easier than using a map to identify arrivals, while it identifies departures well in advance. While both FlightRadar24 and Planefinder have some form of departure and/or arrival boards available either natively or as an in-app purchase, I have found both to not be the most user friendly solution available. FlightRadar24 only provides an arrivals board for flights enroute, while Planefinder has both arrivals and departures but seems to show roughly half of the number results as FlightRadar24. Both are also locked in to sorting by arrival time, and are limited only to relatively major airports. Instead of using either of these apps, I rely on FlightTrack Pro which is far more flexible in my eyes. This app, while designed more for travelers than enthusiasts, has a very comprehensive arrival and departure board capability that is sortable by airline, origin/destination, gate, and arrival/departure time. It also lists flights from even very small airports.
Air Traffic Control
While I wrote previously that I strongly prefer to use an actual scanner while I'm out in the field, I do still find LiveATC.net to be a very useful tool in both the website and app versions. For spotting purposes, I typically start listening in my car while riding to the airport to find out which runways are currently in use so I can finalize where I am going well in advance. It also helps me to get focused on what I am going to be doing that day. Once I get to wherever I will be photographing from, I turn the app off and the scanner on. An added bonus with the app is that each airport has a button that shows a diagram of the runways, taxiways, terminals and other buildings. The app also includes a list in each channel of which frequencies are monitored which can be useful in programming a scanner. Another frequency database that is useful for scanning is the excellent radioreference.com, which lists pretty much every scannable frequency used anywhere, including in aviation.
The Aircraft Communications Addressing and Reporting System (ACARS) is a tool that I have only begun using relatively recently. Designed for data communications between aircraft and the ground, the data can be decoded to find out various types of information on a flight. For me, the best use is to find a website that provides a filtered form of this data, such as the Local Airport ACARS Monitor (LAAM), which will provide flight numbers, registrations, the origin of the flight, and the ETA. However the most useful tool for me is the ability of this site to highlight which specials will be arriving or which have already arrived. Since ACARS data is only broadcast when a flight is operational, I find this tool most useful if I check it periodically throughout the day. Unfortunately, there is no centralized ACARS website, so you need to find a site for the airport that you are interested in, if one even exists. LAAM provides data for airports in the New York, Philadelphia, and Baltimore/Washington areas.
There are a few other tools that I use on a less frequent basis. The Airline Codes Website is a searchable database of pretty much any of the codes and call signs that are used. Hear an unknown callsign on the scanner? Type it in here and it might tell you who it is, though it doesn't always work with some of the more obscure ones. Another useful tool that I have found recently is the Spotters Wiki. While I still prefer the spotting guides from NYCAviation for New York, for other airports around the world, Spotters Wiki is a great place to get information on spotting at different airports. Another source for finding planespotting locations is the Planespotting Location Guide, which has information for many of the major metropolitan areas in the US.
Although I have Lightroom 4 on my home computer, I find that I do much of my editing on my iPad after importing my photos with an SD reader. After doing an initial weeding with the stock Photos app, I move in to the iPhoto app for most of my editing. iPhoto is a surprisingly powerful tool given its simplicity. After applying any cropping that might be necessary, I can easily make adjustments to exposure and white balance settings, as well as adjusting saturation and sharpness. If there is one fault, it's that exporting edited photos to anything other than the onboard camera roll is very buggy. I typically export to the camera roll and then upload to Flickr, Facebook, and my blog through each service's individual apps. Another excellent app for photo editing on the iPad is Snapseed, which has recently become free. While the tools are very powerful in Snapseed, the editing controls are a bit less intuitive than iPhoto. However I plan on using Snapseed more than in the future, and perhaps even write a full comparison of the 2 apps.
So there are the software tools that I use for planespotting. Have an app or website that you love to use that I didn't mention here? Chime in in the comments below.