I have written two novels (unpublished) and about to start a third.

These days I use a minimal writing app called iA Writer. The file is saved to DropBox automatically and I also push commits to GitHub everyday as a way to keep track of revision history. A nice clean system that provides backups and no distractions from the writing itself.

When I am working on a novel I do a few things that help me immensely to keep the momentum going, which is really important:

1) I don't revise anything as I go. 2) I have a min/max daily word quota. 3) I write at a specific time each night (for routine).

Before I discovered those practices I started so many writing projects I never completed.

Good luck to you!