Variable velocity thrue life is a major feature for particle. You can add this non exhaustive list for variable velocity in the mesh , ribbon and texture super tools , setting keyframable of course :
1- ''Velocity thrue life particle'' which would break down into 2 sliders ranging from 0 to 100 :
    - Mass :   0 = linear velocity , 50 = 1/2 of velocity ,  100 = no Velocity (Stop)
    - Mass  thrue life particle (Mass ratio?)    
               0 = Mass applied at the beginning of the particle's life
               50 = Mass applied to the half life of the particle
               100 = Mass applied at the end of the particle's life
2- Velocity inherit :  0 = no velocity heritance of the emitter
                                   100 = total velocity heritance of the emitter
3- Adding a vectorfield influence:     0 = no influence
                                                               100 = total influence
                                                               Ability to change the vectorfield in Iclone
4- Change the existing billboard Atlas from 32 to 64 (8x8) with horizontal reading and not
     vertically. All Udk or Unity Atlas are horizontal animation reading.
5- "Vortex". Possibility of emitting particles heading towards the center of the emitter shape:
               Sphere, cylinder, circle, custom mesh. Would it be possible to add this function?
Video example that could be created  with  the emitter super tools with this features  :   
https://youtu.be/-XmLZV7AcCI