transmitter of DIY ir for ipad?

I think the real challenge would be the design and construction of the IR hardware, as point out you. The components are fairly good markets and the design itself is hardly a challenge. The real question would have written the app which would be necessary to control the IR device.

If you feel like learning how to develop your own applications you can make free of charge. Go to iTunes on your iPad, click on "iTunesU" to the right of the bottom, select universities and colleges, and then scroll down to Stanford. Right scroll through courses and you will find a two-part, 25 conferences-party iPad apps programming course. It's free and, at the end of the course, you will be able to program simple applications yourself. It is an excellent resource for one of the best universities in the world.

As you will see it, the app development is a fairly complex process requiring significant experience in programming and access to a computer Mac, iPad SDK and registration with the Apple Developer program.