iPhones, iPads, and Android phones and tablets can make great Japanese dictionaries unless you need to use them intensively. But if you're studying Japanese seriously or need to read a lot of Japanese for your job, life in Japan, or other interest, the limitations of those devices will become frustrating very quickly. The short of it is that the screen tech that allows them to be so responsive to fingertip gestures isn't great for Japanese handwriting recognition, and if you frequently need to look up words written with kanji you don't know, you need excellent handwriting recognition. The old Windows Mobile OS has excellent Japanese handwriting recognition: it works quickly and is extremely tolerant of mistakes, finding the kanji you want the first time almost every time--and it almost never fails to find it after a second effort. Even the best apps on iPhone and Android require you to write more slowly and carefully (because you're trying to draw intricate little shapes with a big fat fingertip), often require you to try over and over before finding what you're trying to write, and much more often than Windows Mobile fail to find it all, no matter how many times you try. Steve Jobs hated the stylus, but if you need often need to look up Japanese words you see, you'll love it. Beyond that, the best dictionary app for Windows Mobile is better than the best for either iPhone or Android (the best for each is a version of EBPocket Professional)--the new smart phones require apps to look simple, to avoid scaring off computer-phobic customers, but the ironic result of that is the dictionary apps for those phones and tablets have to hide some features and options away, making them harder to access, and they even have to shed some important features. So on a Windows Mobile PDA, compared to either an iPhone or Android, you've got more convenient and more capable handwriting recognition and a more powerful and convenient dictionary app. With the Galaxy Note Android phones and tablets, you do get a precise stylus that works well with an available handwriting recognition app--not quite as well as Windows Mobile PDAs, but close. But with the Note, there's still the problem that the dictionary apps lack some of the features you can get on Windows Mobile. To be fair, the Galaxy Note is a close second to a Windows Mobile PDA, and good enough for all but very intensive use--if you're translating or studying literature, it could still get frustrating.
The downside or a Windows Mobile PDA is that it can be difficult to set up for Japanese dictionary use. These days, it's also getting hard to find a good one--they stopped making them a few years ago. The easiest approach, and the way to be sure to get the best set-up possible, with a warranty, is to buy one all set up and ready to use from Japanese Language Tools. However, it is possible to set up your own.
The most important thing is to get the Japanese version of whichever PDA you choose--if you start with a Japanese PDA, it's actually easier to set up than an iPhone or Android. But Japanese-OS PDAs are hard to find and typically cost a lot more than English versions of the same models (prices for used PDAs in Japan are crazy). If you buy an English-language WM device, it won't be able to read and write Japanese right away--it's possible to install good Japanese support on some English-OS WM devices--but it's a bit different for every device and takes a bit of hacking. You can also convert some English-OS devices to the Japanese version of WM, but doing so yourself entails some difficulty and risk and is not possible for all models--see here for more info and instructions for a couple of Dell Axim models you may be able to find used for a good price. You should also think about the display resolution: the standard 240x320 QVGA displays are OK and compare well to standard electronic dictionaries, though not to modern retina displays, but the dictionaries (and everything else) will look much better on a 480x640 full VGA display; if you want to do more with your phone or PDA, especially surfing the web or using GPS navigation, VGA or better is a MUST. Size also counts: on anything with a 3.3" or smaller VGA or QVGA display or a 4" or smaller WVGA display, kanji can be hard to read and using the onscreen keyboard and handwriting entry is difficult. On used PDAs and phones, avoid Windows Mobile 5.0--users are reporting instability and bugginess; WM 2003, 2003SE, and WM6 are reliable, rock solid on most machines, and just as capable, so stick with those. And, finally, you need a big memory card--a full slate of dictionaries can take well over 2 GB, so you should really pick up a 4 GB or larger card so you'll have room to do other things with your PDA, too (music, movies, GPS navigation, etc.). For making your own system, the Dell Axim X50V with WM2003 OS is probably the best buy, as the English version can be converted to Japanese without terrible difficulty, it's got a great VGA display, it's a good size to carry around, and dual memory slots means you can pack up to 68 GB of memory cards in it at once. DO NOT get an X51V unless you're fairly skilled at hacking operating systems--it comes with WM5.0, as mentioned above, and the Japanese version of WM5 on the X51V seems to be particularly unstable. While it runs beautifully if updated to WM6 and hacked to add Japanese, doing so is complicated and requires some experience in rewriting operating system code (none of the off-the-shelf WM6 upgrades work perfectly until you've gone and tweaked the code a bit; and some upgrades aren't compatible with the hacking necessary to add Japanese). Click here for a fuller discussion. If you haven't bought a PDA yet, take a look at my offerings--an X51V working beautifully, fully Japanese-capable English OS, with all dictionary software and dictionaries already installed and tested; and a Dell Axim X30 with the Japanese version of the WM2003SE OS, all set up and ready to use with the same dictionaries, dictionary software, and Japanese entry as the more expensive X51V version (all JLT PDAs have been factory refurbished to new condition and still make the best Japanese dictionaries money can buy.
First, install a dictionary reader program. I've tried and rejected almost every WM program out there. Most are terrible, and most of the ones that aren't bad work only with expensive but mediocre dictionaries sold by the program maker. The best program I've found is EBPocket. Because the large commercial Japanese dictionaries come in or can easily be converted to the EPWING format EBPocket uses and the program itself is excellent, that's where I've put my efforts. Here are instructions for setting up EBPocket, and here for using it. Don't actually start EBPocket for the first time until AFTER you've put the dictionaries you want on your memory card. Unfortunately, the developer no longer sells the Pro version, so if you set up your own dictionary you're limited to the free version, which is missing a few important features. I've got a license from the developer to continue using the Pro version on the systems I sell, provided I take care of all support. I don't have a license to sell just the program, only complete devices with the program already installed.
Now, you need to get some dictionaries. The JLT dictionaries form a pretty comprehensive set (click "screenshots & details" next to each for a fuller description of each dictionary; all except Eijiro and Conjugations, which are available from JLT in the JLT package, are free). Most of these are based on the Edict project from Monash University and Prof. Jim Breen, extensively modified and converted to EPWING format by me. There are two Kanjidic options--choose one or the other, not both.
Very important: Each EPWING dictionary is an entire folder with various files and subfolders inside. After unzipping the download, leave everything in the dictionary folder alone--moving or renaming anything or trying to open a file directly with any program will break the dictionary. When copying or moving a dictionary, be sure to copy or move the entire outermost dictionary folder--again, don't mess with anything inside of it and you'll be fine. Now, when you start up EBPocket for the first time, it'll automatically find and set itself up to use all the EPWING dictionaries anywhere on your device. If you've already been running EBPocket and want to add another dictionary, use the obvious "Add Dict" function or, for more control, "Edit Group" from the Tool menu.
You can also buy EPWING versions of most of the major commercial dictionaries on CD. Perhaps more conveniently, from Logovista, you can download some of them in Logovista's own proprietary format, which can be converted to EPWING quite easily using a program called dessed (how to navigate Logovista's site to get to the dictionaries; how to use dessed). If you don't get Eijiro, a particularly good buy is the Kenkyusha Intermediate E>J and J>E dictionary (if you already have Edict and Eijiro, though, the Kenkyusha Intermediate doesn't add much). The Kenkyusha Daijiten is much larger and far more useful, but at 25,000 yen it's quite expensive. Very useful, at least for high-level students, is a good kokugo jiten like Koujien or Daijirin. There are also good commercial French<>J, German<>J, Italian<>J, and probably many more dictionaries available in EPWING or Logovista format.
Finally, there are all sorts of EPWING dictionaries available for free online. Some of them are versions of the same dictionaries I've used (Edict, Enamdict, Kanjidic)--I think mine are quite a bit better, obviously (if I'd thought what was already available was great, I wouldn't have spent months making my own). However, some of the other choices are interesting. Note that these aren't my work, I haven't even tried some of them, and therefore I can't make any promises about them. Maximilk's site is a good place to start. See the "other dictionaries" page for descriptions and links.There's even a free Sanskrit-English dictionary there.
Shrink your dictionaries. EPWING format dictionaries are huge memory hogs--use a program called EBShrink to shrink the dictionaries into the much smaller .ebz format, which works just fine in EBPocket (shrunken dictionaries have the full contents and run just as fast as unshrunken ones). EBShrink comes as a free helper file included in the EBWin package, which you can find about halfway down the very long EBPocket page (install the unicode version). EBShrink is pretty self-explanatory, but click here if you'd like instructions. Note that my dictionaries are all pre-shrunk and ready to install--DON'T try to shrink them again!
Install your Dictionaries. First, if installing to an SD card, you must format the card. The best way is in the PDA itself using the CNetX FlashFormat program, but a digital camera will probably do in a pinch. If you don't format it, or format it in a Windows or Mac computer, it'll seem to work for a while, but then your files may start disappearing from the PDA. Each dictionary is an entire folder--don't rename, move, or try to directly open anything inside it--just put the entire folder anywhere on your memory card (except My Documents), then open EBPocket and access the dictionary from within the program. If you install the dictionaries to the card before starting EBPocket for the first time, it should find them automatically. To add dictionaries later, use the "Edit Group" function in the "Tools" menu.
To make your own EPWING dictionaries, click here.
And the Sharp Zaurus? I don't know much about it, but I do know the Japanese versions have kanji handwriting recognition built in, and that it's supposed to work very well. Also, the Zaurus has a dictionary program built in, so just put some EPWING dictionaries on a card and stick it in and you're good to go. However, the Zaurus is a saurus these days and I don't know if it's up to running huge dictionaries like Eijiro. I don't even know if it's capable of holding a memory card large enough to contain Eijiro. There are some resources listed on Jim Breen's Japanese page. In addition, the PDIC .dic format files for Eijiro and the files I made for WDIC might run on ZPDview for the Zaurus (again, whether or not ZPDview works with recent Zaurii is unknown). There may be other programs that can run PDIC files as well--it's worth looking into. Armin Rump's excellent site (which provided the key information I needed to make my Edict files work with WDIC) has clear and useful information for using Japanese dictionaries on the Zaurus.