So far the textbook lists and custom lists for Japanese that I've tried don't have the romanized spelling. Is this a feature that has yet to be implemented or are the lists just lacking it?

If it's there and I'm missing it, sorry for the post and please point it out to me >.>

All kana for now, no romaji. Perhaps you can give some feedback? What is your opinion of romanization vs. kana? Is it a must-have feature, a slight preference, or something good to have when starting out?

It is essential to know kana in Japan (especially if you plan on going to the grocery store). From my experience I actually pronounce words better when reading them using kana. This is because I better make the distinction that it is actually another language rather than a modification on English sounds. I am much more likely to pronounce the elusive Japanese "R" sound if it is written as ら、り、る、れ、ろ.

It might be good to be able to turn on an option which allows the user to hover over and view the romaji. I think it is very important to make them hover over, because this will make them work to make the connection and lose the dependency.

Lastly, it is fairly easy to write a small piece of code to handle the translation from kana to romaji since it is nearly a set formula (except when you get into は=wa). This is my opinion and it essentially comes down to kana being essential to pick up quickly if your serious about truly learning the language.

Once you get to know the Kana using roman letters can be annoying and counter productive for learning...

I would certainly suggested the poster go learn them ASAP as it will really help :)

Yeah, my impression was that kana were one of the first things students learn, and in fact the textbooks I use (Genki 1 and 2) completely stop using romaji after lessons 1 and 2 when you're still learning hiragana and katakana. I haven't seen romaji used in textbooks except for that instance, though I haven't seen too many! It's really crucial to learn them before you can get far in reading Japanese.

So no plans for the time being. If it were completely 1 to 1 translation, it might be doable but given those exceptions it would add too much complexity to make it work.

One thing I would like to do at some point is make it so that you can practice reading your kana on Skritter. That will be useful for people just starting. I'll see about adding that soon after reading and definition practice is built. Unfortunately, because hiragana is a cursive script, we can't have Skritter teach writing, so you'll have to learn that one the old fashioned way!