My world on the web
There are so many great games and online tools designed for younger students. Once students begin recognising the alphabet, I think they can begin learning to type. This can complement your teaching of traditional writing and literacy.
Some schools of thought suggest that typing might be the new cursive. So instead of investing time in teaching students how to join their writing in middle primary school, perhaps there could be more of a focus on improving keyboarding skills.
It feels like we spend so much time debating handwriting sometimes that we forget about typing. I really like how you compare the different applications in a concise fashion.
You might be interested in this post from Catherine Gatt, in which she reflects on the development associated with learning to type.