My Language Notebook is a free program I heard about the other day that helps you to keep and organise notes on the languages you’re studying.
You can use the program to make notes of sentences and longer texts, add translations and notes, and also record audio. You can also upload your notes to the site to share with other learners, and download notes made by others.
This has potential to be a useful tool, and the author has plans to add more features, such as a spaced repetition system.