Fellow language enthusiasts,
I have just incorporated the awesome Eldamo dictionary from Paul Strack (eldamo.org) in my transcriber: http://arno.org/tengwar
Typing a word will give you both a transcription of this word in Tengwar, as long as a list of entries from Eldamo matching your input.
Type a word in english to find translations in a number of languages, including Sindarin, Quenya and more. Or type a word in Sindarin to find related words, or the translation in English.
Looking forward to your feedback and suggestions for how to improve it.
For anyone interested, I also have a REST API available, just let me know if you want details on how to use it.