This year, ladies and gentlemen, I present to you ScrabbleScore -- simple application that calculates your Scrabble word scores according to English language scoring.
It works on .NET Framework 4.6 and was created on Windows, so Windows runs it smoothly. It can be run on other OS (Linux with Mono, for example), but untested.
Just enter the needed word and look at the score. To mark letter as "double-letter" or "triple-letter", just put number 2 or 3 before it. To mark word as "double-word" or "triple-word", just put 2 or 3 at the end of the word. If there are several letters in a row, only the last one counts.
Screenshots:
Source code:
https://github.com/UrbanLlama/ScrabbleScoreCSharp