There are many programs that you can use for 2D animation and related support.

I’ve listed some below that are popular.

Not that you need all of them but, depending upon your projects you might find that you do need some of them for various reasons.

You do need at least a photo editing program if you want to modify your actors and create props.

A drawing program like DrawPlus is also useful to create custom actors and props.

Animation

CrazyTalk Animator 2 Reallusion

Photo Editing

Photoshop Adobe

PhotoPlus Serif

Sound Editing

Audition Adobe

Audacity SourceForge (Free)

Vector Drawing

DrawPlus Serif

Adobe Flash Adobe

Movie Editing

MoviePlus Serif

Studio 9 Pinnacle

Special Effects and Utilities

After Effects Adobe Photo/Visual Effects

MorphVOX Pro Screaming Bee Voice changer

ParticleIllusion WonderTouch Visual Effects

BluffTitler Outerspace Software Titles

SWF Decompiler SoThink Decompile SWF files

Xara 3D Maker Xara Titles

FL Studio (FruityLoops) Image-Line Music Loops

There are many other programs out there that are either free or for money that can also be used.

The list above is by no means a must have (except for CrazyTalk Animator) but is presented as a guide and for suggestions of what to use.

If you have any questions please contact me.