How was this slow motion effect created? what programs can do this? In the video they seem to be creating new frames inbetween the medium's original frames and then slowing/speeding it up with speed control.

It looks like the equivalent of going every frame and defining a new frame that's a gamma cross between the surrounding 2 frames.

Simply increasing the fps or changing the speed alone can't facilitate this effect. What programs can do the effect as shown, and what's it called specifically? Or do they manually have to take 1 frame, toss it in a vector image editor of some kind and create all those inbetween frames?
There are methods to generate frames in between frames, mostly giving you mixed results.

For one, the plugin "twixtor" (~330$) actually does a somewhat decent job at assuming missing frames, so much so, that a 30fps video can be played back at half the speed, making it look like 60fps slow-mo.

On the other hand side, you can sample the frames directly in premiere for example. I wouldn't recommend it however, as the results don't usually live up to the expectations.