Removing switched outlet and 4 terminal outlet with 2 terminal outlet?
Coloring is often unreliable. But in this case, it appears colors are being used consistently.  In all cases: 


White is neutral
Black is always-hot
Red is switched-hot (or rather, was.) 


It appears supply hot and neutral enters the system at the light switch.  Always-hot, switched-hot and neutral is carried from the light switch to the pictured receptacle.  Then, always-hot and neutral are carried downstream to the next receptacle (not pictured).  

Your old receptacle has a "broken off" tab separating the screw terminals used by red and black.  This allows hot to be controlled independently on each socket of the receptacle. 

You are familiar with wire-nuts and pigtails, as you are using them in the former switch location.  

That short length of black wire between the yellow ribbed and red wirenuts is superfluous.  You can add the red wire to the red wirenut, and liberate a yellow wirenut and a pigtail.  Wire nut colors indicate size (number of wires they can handle) not function. 

I gather your new receptacle only has one hot and neutral screw. (USB?)  Therefore you will need to pigtail neutral to the new receptacle.  Ordinarily I would say you need to pigtail hot as well, note that it is already pigtailed.  You could continue with that, and simply cap off the red, as it is redundant and you are not allowed to parallel wires.  However, instead, I would remove that pigtail, leave only the two blacks spliced to each other in the back of the box, and land the red wire on this receptacle.  That will give the red wire something to do.