I know I've been going on somewhat about aedict 3 recently, but it has been developing at a considerable rate lately, and after giving it some more thorough use, I thought it worth a little note here.
I'm not sure exactly when it was brought in, but aedict now has a "live search" function. When I read that in the changelog, I wasn't particularly impressed; I figured how much time does it save having to not press a button? However, it is surprising how convenient this little feature is!
Firstly, I found the time savings are actually fairly considerable in most cases (qualitatively speaking). However, what I love most about this feature is that it provides a text glossing functionality akin to the Electronic Dictionary Research and Development group's very own site*.
What is the fuss about text glossing? Well, a lot of well-known apps like "Kingsoft Office" and "Adobe Reader" are terrible at selecting Japanese text. The problem appears to be that they are used to separating words by spaces and punctuation, as we do in English. However, Japanese doesn't use whitespace characters, and so when you hold your finger on a word in either of the above programs (and I'm sure they're not the only ones**), it selects between the two nearest punctuation, which might contain several words.
After selecting Japanese text in such a program, you then have 2 options: Firstly, you can use the fiddly text selection controls to highlight just the word you want to copy into the dictionary. Secondly, you can copy the whole sentence, then edit it once you've pasted into the dictionary.
The advantage in having text glossing is that you can just dump the whole sentence into the dictionary's input box, and you get a translation of all the words in the sentence. No fiddling with text selections, no editing of the sentence; a huge time saver, especially considering the text glossing is included in the live search, so you just paste, sit back and watch the magic.
Ultimately, my praise here is as much a reflection of my frustration with other programs (such as Kingsoft Office and Adobe Acrobat) that do the bare minimum to support Japanese text. Nonetheless, if you do a lot of work with Japanese documents (I do some freelance translation, and read the odd scientific article**** in Japanese), then you will frequently need to work around this problem. Aedict3 has made this process about as painless as I expect things will get, and for those who do a lot of reading of Japanese on their android devices, I highly recommend dishing out for Aedict3.
* For the unaware, the EDRDG is the home of edict and JMdict, which is integral to aedict. I'm not sure about the specifics, but without it, and the work of Jim Breen, we'd probably be a lot poorer in the dictionary department.
** Because how do you write a program to detect word edges in Japanese? It would be very difficult, I think. A work around would be to only select contiguous kanji characters. This would make selecting hiragana words more difficult***; however, because hiragana is phonetic, it is easy to reproduce by typing elsewhere, if needs be.
*** you'd have to drag the selection over the characters you wanted, which people do when they want to select more than one word of English anyway. So not spectacularly more difficult, really.
**** scientific articles are commonly distributed as pdf files.