"Panels are great, but how do I change this one page?"

In a hurry to get this information up... Sorry for any typos :)

This module lets you take the input from a field and allows using HTML and token replacement (or alternately PHP) for display.

"File entity provides interfaces for managing files. It also extends the core file entity, allowing files to be fieldable, grouped into types, viewed (using display modes) and formatted using field formatters. File entity integrates with a number of modules, exposing files to Views, Entity API, Token and more."

I just read a great article on this that breaks things down very well. You can find the original article here: http://fredparke.com/blog/create-your-own-tokens-drupal-7

Basically, you need to use two hooks. The first one tells the system about your token. The second one contains the specific logic for your token.

Otherwise known as ECK, Entity Construction Kit allows the creation and management of new fieldable entities in a UI.

Entertaining presentation on usage from DrupalCamp London 2014: http://youtu.be/hhUuv1cEgVY

The media module allows changing allowed file types that can be loaded when using fields but not at /file/add. So, here's how I got around that:

"Maxlength allows you to set maximum length of any field on any form making use of the form API. This includes fields created using the UI. (Example: any text field on a node)

"Geofield is a module for storing geographic data in Drupal 7. It supports all geo-types (points, lines, polygons, multitypes etc.)"

"This is a very simple module that adds a 'weight' field to the tables already used by the excellent Flag module. This weight can then be used to provide ordering of flagged items. This module also provides a Views field which can be used to sort flagged items. One interesting use of this ability is to integrate with Draggable Views to create a user-sortable list of flagged items"