I really wouldn't rely on a machine to correct you even if there was something like this. Computer languages are completely understood by the compiler and/or interpreter, which can tell you if you've made an error, but are VERY simple compared to the grammar and syntax of a human language (which often has a multitude of exceptions, unlike computer syntax).
Word misses spelling and grammar mistakes because even though something may be correct/incorrect in actual usage, the rudimentary way in which Word checks your syntax and spelling has a really hard time determining whether the way you're trying to use the language is right or wrong.
I will agree that Rosetta Stone isn't the greatest, but its method (full immersion) is actually a good one. The main problem with it is that it gives you absolutely no direction on HOW to use it effectively.
The Genki textbooks are good, and my school has recently started using Nakama. If you want to be corrected, then keep posting on here and asking questions; try Live Mocha or Lang8; or just dive into a class, that's what they're there for; to help.