BOUSOZOKU  This is exactly the kind of tool that helps with the varying simplication of Chinese characters across countries.

Since Japan and China have gone separate ways to simplification and Taiwan still supports traditional characters, it's often important to have a bridge. This product is that bridge, especially for someone who is younger than the changes.

I find it invaluable when dealing with Simplified Chinese from a Japanese background.  
(Version 1.2)

BILLYFUSTER  This program is an essential tool in the arsenal of students, scholars, and multilingual users who need to work with traditional and simplified Chinese, classical and modern Japanese, and/or Korean on the computer.

Often times online databases or dictionaries restrict you to entering one of these forms (i.e. simplified Japanese versions of characters), but if you enter, say, the traditional Chinese version of the same character, you're stuck. Rather than activating another input method, you can paste your character into this program and get the variant that you need. It also helpfully lists pronunciations and basic meanings of characters.

The program uses Unicode.org's unihan.txt as the basis for its database of variants as well as other publicly available lists on the net. None of these lists is 'complete' (the problem of variants is an ongoing unresolved CS/linguistics nightmare), but this program is very practical in 99.9% of cases.

The developer is very kind and developed this program for free. Please share your appreciation by letting him know.  
(Version 1.0)