Spitzer Tools

Of course, the main, most important Spitzer tools are Spot and Leopard.

Point Source Magnitude to Flux Density Converter
cooswitch.pro is an IDL routine that converts celestial coordinates from decimal degrees to sexigesimal format, or vice-versa. It does not apply any corrections for proper motions or precession, merely transforms given coordinates from one format to the other. It may be useful when configuring peak-ups in IRS AORs, as described in the Spitzer Observations Planning Cookbook.
Coordinate conversion and precession (from Chandra)
Date conversion tool (from Chandra)
Tool for performing IRAC pixel coordinate/pointing offset transformations.

AOR file parser (perl script) - useful as an aid in preparing the obs ervation summary table portion of your proposal!

IPAC Table Format tool (reformat your ascii input table)

Notes on PCRS Guide Star Catalog (PCRS-GSC)
Explanatory Document for the catalog (This document describes the contents of the PCRS-GSC; in particular, it gives the format, units, and description of each of the table columns that constitute the catalog.)
the catalog itself (v. 2.4f)
Use of the PCRS-GSC is described in detail in the IRS chapters of the Observation Planning Cookbook

(useful for IRS observations)