BalanceRun is currently in Version 4.1 and will develop and enhace with time.
Once purchased, you will recieve updates for free, as they will simply be uploaded into the package you purchased. Each Update will come with an email notification to all customers.
So to get the newest Version just redownload the pack from your purchases site on Blendermarket.

Prepare your scene:
In order to use Balancerun, you will need an armature, and an animated target-object, which guides the character. So all you need to animate is the position and rotation of the target object.
It is crucial that you have a quick frame refresh rate. Hide and disable everything you can, to speed up viewport rendering, as the addon has to swap frames often. 
Currently the addon hides all objects using the armature which is simulated and lets tehm appear, once done automatically. 

If your animation of 1000 frames takes much longer than 30 seconds to calculate, then something is taking the viewport too long to refresh (particle sytems, subdivisions, armature modifiers, corrective smooth modifiers...)
everything that slows down the viewport will slow down the calculation. 

You'll find te menu of BalanceRun in the UI Shelf of the 3dView (righthand side) 
in the NM-8 tab.


The menu:
All buttons and parameters are described in the info box, that appears when you move your mouse over them. So you wont need to study everything in detail.  

The menu is split in three main sections, that resemble the workflow:

Define all targets in the "targets"
 section first. Set the characteristics of the walk in the "parameters" section.
And finally generate the walk in the "simulate" section.


rigify:                                
If you want to animate a rigify armature, just check the "rigify" box on top, and the menu changes accordingly.

advanced:                     
If you are using BalanceRun for the first time, it's recommended to uncheck "advanced" so that you wont be confronted with too many options and parameters. You'll see the most crucial settings.
The rest of the parameters stay hidden and will use standard values.

In this simple mode you will be able to define up to 4 feet and 4 props. In advanced mode you can define up to 8 feet and 8 props.

Props is short for properties, which are the swinging parts and assets of your character. Feet & props can be ik-targets for the head, arms, the tail or a sword which the character carries in his belt.
Props will be swinging since they are pushed by the movement, and they try to stay in their restposition.

Targets section:
follow: 
select the animated object, which the character shall follow. Get sure that the object is placed in global coordinates (so it has no parents). 
If you need to follow a parented object, simpy create a new empty and use location and rotation constraints to the animated parented object, to get global locations.

ground (optional):
Here you can select a landscape mesh to walk and climb on.
Right now it should be just a mesh, without (subdivision) modifiers.
You can help the simulation, if the mesh is only the crucial parts, and the polygons are not too dense, and smooth enough.
Avoid overlaying faces and hires meshes here.

feet:
Here you can manually select the Ik-Targets of the feet. The order in which the feet are stacked here is crucial to the rythm in which the walk will animate.

root:
Usually the rootbone has a "copy location" and  "copy rotation" constraint to an empty object, in order to animate the character.

hip (optional): 
The hip can rotate and swing to achieve twists and contrapost poses while walking.
In rigify rigs the hip bone is called "pelvis" sometimes.

torso, neck (optional):
If you want twist and contrapost poses use the torso bone to compensate the hip rotation. If the head shall not spin with twist and contrapost, select the neckbone in the menu, and it will be animated to look straight forward.

props (optional):
Props are assets and parts of the character that are influenced by the walking motion. Usually these are also ik-targets for the head and for the arms or tail. any object that swings in global coordinates, due to walking can be selected here.
In order to get detailed swinging behaviour you can use the scale of the prop-targets to alter their swinging parameters. See the "Parameters" section for detailed instructions.

Simulate section:
(in simple mode (advanced:unchecked) the parameters will be hidden, and only a swing parameter will be found in the simulate section instead. hence we will talk about this section first.)

startframe: the framenr. in which the simulation shall start.

endframe: the framenr. when the simulation ends. Be sure, that your character has no keyframes after the endframe that move the character.

steptime:
the maximum number of frames that a step needs. Its the slowest step the simulation can produce if the follow object is slow enough. Faster motion of the followobject will lead to faster steps to catch up, automatically.

                                                                      

steptime 5                                     steptime 12                                        steptime 20

if the footobject has polygons it can be used as a particle emitter. 
stones: check stones to emit particles whenever the foot steps down.
dust: Check dust in order to emit particles as the foot steps down. Particles will be created that fly up and drag to ease down.

props only (advanced):
This is the button to just animate the props. Adjusting prop motion wont need to recalculate the feet, to save time.
cleanup (advanced):
If for any reason you need to delete all the animation between starframe and endframe, you can do so by simply clicking this button. However, this is also done automatically if you hit generate keyframes.

generate keyframes:
This is the core of this add on. you have setup everything, and you are ready to run the simulation. Once you clicked the button, the addon will analyze the targetobject, and calulate the walk keyframe by keyframe. you can follow the progress a little bit in the system console (window / toggle system console) to see the progress.
It is crucial that you have a quick frame refresh rate. hide and disable everything you can, to speed up viewport rendering, as the addon has to swap frames often. If your animation of 1000 frames takes much longer than a minute to calculate something is taking the viewport too long to refresh (particle sytems, subdivisions, armature modfiers, corrective smooth modifiers...)
Everything that slows down the viewport will slow down the calculation.
1000 frames should take about 20 seconds to calculate.

Parameters section (advanced):

hip&props:
The underlying physics engine is based on spring dynamics, so the swinging of the hip and props have a harmonic look (like a damped metal spring). To get individual behaviour per prop you can check the scale buttons, so that each parameter is multiplied by the scale of the prop target.

swing:
a general amount of bounce motion. Set this to 0% if you want to animate a robot, and 100% if you want to animate a happy comicfigure.

stiffness: the physical stiffness of a spring. higher values will lead to shorter amplitudes but higher frequencies.
damping: the physical damp value easing down the spring motion. Higher values will stop the swinging sooner.
twist: hip and torso will twist around the vertical axis while walking.
lean: the hip will bend due to acceleration and the torso will compensate.
contrapost: the hip and torso will rotate around the forward axis (local y axis) while walking. resuting in a natural elegant motion.

twist 50% contrapost 0%              twist 50% contrapost 0%                twist 0% contrapost 50%
wihtout neck compensation                    with neck compensation                      without neck compensation

hip balance: the hips location seeks 0 = the follow object, 50 = the middle of the feet, 
100 = the middle of standing feet. Hence 0 results in smooth motion, yet may be offset to the feet a little, while 100 will swing with each step seeking the most stable location above the feet, which are on the ground.


legs:
stepheight: 0% feet slide on the ground and wont lift at all. 100% feet will lift at each step up to the hip. usually a value of 5-10% looks good.
                                                                                                
  stepheight 25%,  ankle -45°                                                           stepheight 50%,  ankle -45°
                                                                      

dynamic:
ok this might be more important, though it just relates to characters with more than two feet. This is the Balance between step / trot / gallop.
Higher values will lead to the character come into a trot and then gallop sooner. Sooner means at slower speeds. So a horse with dynamic 80 will sooner turn to gallop, than a horse at dynamic 20.

feet:

ankle: 
The angle at which the ankle shall rotate to, while stepping.

ankle intensity:
the ankle rotates in a sinus function, which is above the startangle and below the startangle. the intensity defines how much it rotates to and back again. Yet still the ankle-angle is the middle angle which, the foot tends to rotate to.

easelift:
-100% the foot lifts fast and sets down slow. (sneaking)
0% equal lift and setdown speeds. (normal)
100% the foot lifts slowly and steps down quickly. (stomping heavy feet)