Tesselator - Quadrilateral Remeshing
Since this remesher is fairly intuitive and easy to understand, I will briefly present the settings for it.
Particle remesh
It's the only button from the panel, you click it and it start remeshing.
Resolution
This setting control how many particles fit on the object. It affects directly the quality of the mesh but doesn't mean higher is better, with low resolution and higher subdivisions it yields smoother meshes but with bad alignment while with higher resolution and low subdivision introduces good alignment but also creates more wedges and poles on the topology, if you play around with these settings you'll get the intuition of how it works.
Relaxation
This setting tries to improve the alignment where possible, it's quite literally a smoothing procedure.
Subdivisions
As the name suggest, this setting control how dense and detailed the final mesh will be, It is directly related to the resolution and just subdivide the mesh as many times you want.
X Mirror
It Is like the usual X-mirror from blender, it forces symmetry around the red X-Axis.
Use Grease Pencil
This addon also has the ability to control the flow of the mesh though grease, pencil. Just set it to surface and draw the guides on the mesh. If no grease pencil is available, this setting does nothing.
Pure Triangles
If this setting is enabled, the final mesh will be made entirely with triangles, all the settings above still affect the flow though.
Quads and Triangles.
This is only available if pure triangles ins't enabled, it will force the use of triangles along with quads when subdividing. Which creates a more uniform tension on the mesh, good for sculpting.
Advanced settings:
Those settings are quite unstable, is recommended to not mess with them unless you know what you are doing.
Predecimation: The cross field computation is a slow operation for this addon, decimating the model before computing, helps the process run faster, if your model is lowpoly, you can increase this value, but if it's too dense, you might want to decrease it, for example, a source model with 5.000 faces can have a predecimation of 1.0 while a mesh with 300.000 faces might need a value of 0.05.
Step scale: This factor affect how the fast relaxation converges, it just control how fast the particles move at each step, a value of 0.2 means that the particle will move 20% of its radius at each step for example.
Adaptive: This affects the density of the mesh on detailed regions, a high value make curved regions denser and flat regions sparse in terms of vertices.
Particle Placement: This option sets which algorithm is used to place the particles on the mesh, Fast marching is really good at getting good flow but sometimes get stuck on sharp edges while integer grid doesn't give good alignment but is very uniform.
If Fast marching is enabled there will be available an option called seeds, it controls how many starting points will be randomly placed if no grease pencil is available.