More off-topic dictionary talk
For reading on the iPad, there is already a J-J dictionary built-in (スーパー大辞林), you just need to enable it. You can look up words from within Bookwalker on the built-in dictionaries, by selecting the word and then Dict from the pop-up menu. I’d really like more variety though, so I’ll definitely look into buying some more dictionaries in the future. I saw the listing for 三省堂国語 just the other day, but now it has strangely disappeared.
Right? There is a way to share selected text, it just probably takes more time than actually typing the word like you do. It was discussed a little in this thread where I was seeking dictionary-related advice if you’d like to read more.