I haven't found any technical tool under
"indepedent training management" rather mechanical innovations. Firstly, soft ball slows down the features of the ball such as spinning so easier to analyse. Secondly, different field materials help you to understand the behaviour of ball such as spin. Thirdly, a hit wall makes it far faster to trial-and-error different shots because you get an immediate feedback after the rebound.
I tested the stroke-analysis iPhone app but it is far too slow. I haven't found any technical tool to help me here but below the mechanical ways to get feedback about the shots independently.
I. Soft ball
I have used a soft Wilson ball by which you can see profile of the ball easier. This is because the soft ball reacts slower to all hits so you have time to analyse it.
II. Different field materials
Spins have different behaviour in different fields such as Matta (Finnish) and Hiekkanurmi (Finnish). Matta, the red clay mixture, reacts the most for spins so a good way of seeing how much each shot has spin.
III. Hit Wall with different angles
A ball with topspin after the 180 degrees deflection will act as a ball with backspin after collision.
A ball with backspin after the 180 degrees deflection will act as a ball with topspin after collision.
Specific questions about Cameras and other Sport technology
And about the recordings to better see the technique
Whenever possible, ask your subjects to wear as little as possible, or in the
least, have them wear tight clothing that will not mask the true motion of the
body. It can be very difficult to analyse motion if athletes are wearing baggy
clothes. Another way of improving the repeatability of measures taken from
video is to use markers attached to various anatomical landmarks on the
body. Even using a permanent marker to draw on subjects’ skin can improve
the repeatability of measures taken from a video analysis.