~> show a list of guitars (an item having properties of the following types: numeric, string, date, boolean)
~> add or edit item
~> authenticate user
~> provide offline support - persist data on the local storage
~> provide online support - synchronize data to/from a remote location
~> use external services - e.g. show map coordinates on google maps, or send an email using gmail
~> use local services - e.g. camera, sensors
~> use animations