nihongoresources.com
In addition to Japanese dictionary functionality, this website offers free online lessons in Japanese at University level, as well as a free grammar book and several articles of interest to people learning Japanese.
The API server got restored, although with a new API format, so please hang tight while I get that integrated into the original search code.
While this work is in progress, api.nihongoresources.com should at least be working again, while work is ongoing to get that integrated into NR again.