You have patterns you repeat when answering emails and otherwise messaging. These are similar to other peoples but have your style of expression. Today you can already automate these on many devices by using snippets and a shortcut. The only problem is that they are always exact copies, so answering the same person twice will reveal this fact.
A smart snippet software that, while you are typing, analyzes your words and suggests an auto-completion of the whole sentence and not just one word. It will do so with a slightly different variation based on how you started your sentence and your writing style. As you continue writing what it suggests changes until at some point, you choose to use it and complete the sentence or even a whole paragraph.
As a fun game, that develops your mind 🙂
Make a sentence that changes its meaning depending on which of the words you start reading (first, second, etc.)
You just finished listening to a piece of music you liked. Now you would like to listen to something new but similar.
It would be good if I could just type a sentence describing the kind of music I would like to hear next. The app knows the last piece of music I listen to and can analyze my sentence and suggest to me the next piece of music I might enjoy.