Rotoscoping
www.keepvid.com - site where you can download youtube videoes as editable files to use in applications such as Imovie. 
www.giphy.com - Site that allows for simple animation to be created and edited quickly. 
photoshop - The latest versions of Adobe's flagship program, Photoshop, is fully equipment to make animations with you.  Use the timeline window.  The 3 square window layout is easier for beginning, but you'll switch over when you need to use sound. 
Audacity - A free recording and mixing program.  We will probably not get to sound this semester as our time is limited, but just know about this.