There are so many resources available for free, or almost free.
Typing.com is a site that I just can't believe is free because it is so good. It is very thorough, and visual. You can create a teacher account, then assign User ID for each of your students and track their progress.
Each of my boys really enjoy using their own IDs and passwords. On our daily agenda, I assigned 2 to 3 screens at a time, each lesson has between 10 and 12 screens. After they have finished their assigned screens, they are allowed to play one of the many typing games on the site for ten minutes.
The free lessons from Hoffman Academy have been a huge blessing to our family. We started when the boys were in second grade and could read fluently. In the beginning units the parent might want to to sit with them during each video lesson and practice, but they are only ten to twelve minutes and we all look forward to watching the lesson video each week. I am amazed at how much the boys have learned through these lessons in just a short time.
We spend the very small amount they ask for PDF of the printable materials & practice MP3s ($20 for 20 lessons), and it is so worth it! They have recently upgrade their site, to where you can pay membership fee for many more practice extras. So far, we have not felt the need to buy membership, and are still just enjoying the free videos and buys the printed materials each unit.
We finally purchased Rosetta Stone when it was on sale this Fall. But in between lessons, the boys have really enjoyed and learned a lot from the DUOLINGO app. It has voice recognition and several different languages. I don't think it can replace a full language curriculum, but good practice and supplement.