In the past, I have dabbled in sprite-based animations. For instance:

However, that time was about 8 years and several computers ago, and I no longer have the animation software I used to fabricate the above image.
I decided that I was interested in trying my hand at this again, and so I first tried to find the program I had used last time, a program with a free version called Animagic. However, I can find no current website offering that software, and as the alternative appears to be a rapid share link (claiming to contain the program) I think it might just be better to find a more recent, still supported program instead.
As shown above, I'm not trying to do anything overly complex; I already have the frames, I'm just looking for a program (very preferably free) that will allow me to combine them and adjust the timing of the resultant animation.
I have absolutely no knowledge of visual design, so I was hoping someone here would have a better idea as to what software I'm looking for in the first place.