Ojaru-maru: Ojaru to Okeiko Aiueo DS isn't necessarily made for adult learners of Japanese as a second language. In fact, it isn't. It's made for children. But the first thing you learn from trying to learn a new language is that being illiterate is pretty much the same experience whether you're 4 or 40. Materials designed to help kids learn to read in their first language are pretty useful for adults learning it as a second language. Unless they're too hard.
Ojaru-maru DS helps you learn to speak and read very basic Japanese. It contains games that train kids on how to read and write the kana syllabaries, and pick the correct numeral classifier for counting different varieties of objects. There are also speaking exercises that require you to pronounce phrases into the DS mic. It's made for Japanese native speakers, but this vaguely approaches the idea of a My Japanese Coach. It could come in handy for at least learning how to read the Media Create listings every week!