Is mobile iPhone/Android training creating competition for my app development business?

Look at 37signals. They basically gave away the platform they built their applications with. Rails. Sure that's helped create a ton of other folks trying to create applications that compete with their's but what's happened even more is that giving this resource away they've gotten even more publicity which has led to their dominance.

They talk a lot about thinking like a chef. Look at the Food Network. Do you think those chefs teaching all these secrets and recipes on TV and in their books are worried about teaching their next competitor? No. They use all this teaching to make a name for themselves and they capitalize on that name by selling more books + cookware + people eating at their restaurants. Out teach your competition is a gem of advice from Kathy Sierra.

I would continue, the training should provide a useful second income stream and should fortify the skills of those giving the training and boost the reputation of your company. There are always going to be competitors whether they get their training from you or someone else. It could also be a good way of recruiting extra staff - recruit someone who impresses you on the training course.

You mentioned "expand to major platforms" ... android and iPhone are major platforms. Frankly, I wouldn't waste my time with anything else (other than, possibly Blackberry). I agree with Daniel.

Definitely continue - you build relationships with people you train that could lead to other opportunities, including good hires for you. Also, it shows confidence - an important factor in doing business, especially on new platforms.

I would definitely continue the training. Some of those people your company teaches may end up as competition, but even so, any product you design will at some point have competition. Some of your "students" may even end up developing for you. There is no reason to cut off that source of talent and mentorship for fear of competition. And as Daniel mentioned, its nice to have that secondary source of income.

Sometimes the best way to learn something is by teaching to someone else. Your company may come up with a breakthrough idea because of interaction with some of your development students.

Continuing with the training, in the long run will help mature this industry segment, which would help all companies( including yours ) by creating a rich talent pool , ultimately leading to lower development costs. Also, in a mature industry, the cost of marketing also goes down.

You want to be known as "The Expert" in this area, you're going to have to let others know what you know. There will be those that will take your ideas, but others will want you, the expert, to be on their team or build there software. Much less riskier than doing it themselves.

I would continue the training. But pay attention not to share the knowledge that makes part of the competitive advantage.