For those not at all interested in the software, I also share links to the websites of some of my favourite authors for whom writing technology was the quill or the typewriter! At the end of the day it is the imagination that is the most important writing tool of all.
So when it comes to writing, there is no great big magic wand then that will either solve all writing issues or be the one big thing to guarantee any kind of publication success. (I find Scrivener helps me organise my work well and I love their character and setting templates and project targets but it is an organisational tool. Nothing but nothing can beat the imagination).
So how to help "beef up" the power of your imagination then, which I think is the single most useful thing to do to help improve your writing. Dead easy answer here. No big secret. No big surprises. Read! Read fiction in and out of your normal genres. Read non-fiction. Borrow books from the library you might not choose to purchase. If you love said books, you can always buy your own later. But read, read, read. And there really is no short cut there.
After all why do you want to write? Because you love stories. What stories inspired you to take up your pen, writing software or whatever? Think about that inspiration and how you can "grow" that further. Then you won't be stuck for things about which to write. What you will run out of is time!