I use Piknic for blending, is there a "blend" tool option on there?

I don't use Sketcher, but I can basically tell you what they did...

They took pieces of screenshots (or in some cases the whole) and either "cut them out" and/or changed the transparency.

(Each image is done on a different layer.)

Also you can use filters including things like blurring, oilifying, and so many others... Essentially, you really need Gimp or Photoshop to do this. I use Gimp 2.6.11 myself for these.

It's a free program, and I can give you a completely trustworthy link to download it if you pm me. I hope that this helps explain and answer your question! ;3

I use GIMP 2.6
It's free and you can come up with stuff like this easy with layers and fading some of the photos.

I know a few people who have made images like this with GIMP, but I never have because i'm too impatient.

i dont realy know about this but have you try using the adobe flash player