Up until about a year ago, the only writing app I used was BBEdit. The combination of the glossary and hot-keys meant I could make it do whatever I needed it to, quickly. I really felt it was all that I needed. Still, a friend urged me to try out Scrivener, the seemingly ubiquitous writer's app. Be it playwrights, novelists, scriptwriters, or technical writers, it seemed that everybody used it.
The lesson here is, if something seems to be ubiquitous, there's probably a very good reason. Unlike BBEdit, I didn't have to lift the hood to make Scrivener do anything because it did it all already, In fact, it does so much that the $50 price tag that seemed a little steep, now seems like an incredible bargain,. And unlike many programs that do a lot, Scrivener manages to keep a clean, intuitive interface (even though it comes with a tutorial, I managed to figure out everything I wanted out of it with little to no fuss, and no tutorial).
Thus far, I've only mentioned things that were possible with BBEdit, just easier with Scrivener. but we deviate from that with one very important aspect; organization. Basically, if you write out-of-order like myself, Scrivener is your new best friend. You can chop your manuscript into chapters, scenes, paragraphs, sentences, LETTERS and arrange. re-arrange, and re-re-arrange to your hearts content all via drag and drop. Getting my manuscript in order used to be a nightmare. Now, I kid you not, it's actually kind of fun.
In fact, there's your review: Scrivener makes an aspect of writing kind of fun. I can't think of anything that glows more than that.
PS If it ever crashed, I don't remember it happening. It certainly never had a crash that lost work, those things I don't forget.