I will be using Animation Shop 3 for this tutorial.
With this program you will be able to get two images together and animate them.
Open the images you want to animate, in my case, I will be using two (both images must have the same width and height, or else the animation won't look good):

Copy the second image and paste it right after image 1 by clicking image 1, then: Edit > Paste > After Current Frame, and you'll have something like this:

Now click on the icon that looks like a film strip.

A new window will appear with your animated image. If it's too fast, what you have to do is change the frame's time by right clicking one of the images or all the images you want to change the time to. In my case I will just right click on the strawberry with the eyes opened (image 1) because I want this image to stay more time than the one that is blinking, since I just want a fast blink:

A new window will pop up asking me what time do I want the image to stay. I will fill it with 100, but you can change any number (as you can see, the default time is 10).

Now let's click on the film strip icon again and see our animation

Now we have to save it, and to get a better quality on the images, go to File > Save As, name your animation and click save. Then a new option will appear, click on the Customize button and get your settings like mine:

Click Ok, and after that you will have to click "Next" three times more and then just click "Finish".
If you had any questions about this tutorial, please feel free to contact me.