Just to clarify,
SQLite is the database platform chosen by AirNav (and, prior to that, by Kinetic) to host the data embedded in their respective products.
SQLite is a pretty standard implementation of
SQL (Structured Query Language), an industry-standard language for defining and manipulating databases and the data therein, with other probably better-known implementations including MySQL, Oracle, SQL Server, etc)
There are dozens of utilities available to allow a user to interact with an SQLite database using SQL commands - some are free and some are shareware or commercial products such as SQLite Maestro. Similarly, some have a nice GUI front end to make the data definition and manipulation process easier, whereas some are fairly crude (but equally powerful) command-line tools which demand a bit more knowledge of SQL.
My personal preference is for the latter (see
www.sqlite.org/download.html), but that's probably a result of having lived and breathed SQL for the last 20 years :-)