Sports Tactics Board is a Home & Education software developed by Robert Turner. After our trial and test, the software is proved to be official, secure and free. Here is the official description for Sports Tactics Board:

Sports Tactics Board is a utility that allows coaches, trainers and officials to describe sports tactics, strategies and positioning using a magnetic or chalk-board style approach. Supports soccer and hockey so Far, other sports can be easily added.

Features (Release 0.2.1005)
Supports more than one sport (Currently Soccer, Hockey, Volleyball), more to be added.
Records sequences of positions for documenting tactical strategies or plays.
Save and loads tactical sequences from files - allows building a Library of plays or drills.
Supports pre-defined layouts that position players, ball/puck and officials.
Supports exporting images and image sequences to files or clipboard.