I really agree with Krakatoa on this subject. The athletic pitcher program is great for any player that wants to increase his or her arm strength. On top of that you will be working on the continued health of your arm with this program. It also incorporates or suggests long toss along with this program.
The second program unbreakable abs, is also highly recomended, we have been doing this one for less time but the kids, including my son, that are using it swear by it. Having bought it from Jon Doyle I have been impressed with his program but also his ability to answer any question in regards to physical training.
One thought on the athletic pitcher program, you should use this with a qualified person monitoring what you are doing. Both programs also use a mental approach to the work you are doing.
As far as parents having to lay our a few bucks, well yes this is true, however I would rather lay out a few bucks for good quality instruction for a son that is willing to work hard to improve than money layed out for a trip to the mall or worse yet the orthopedic surgeon becuase I did things incorrectly or cheap. Honestly botj programs are realtively inexpensive. Good luck!