Latex

LaTeX is a high-quality typesetting system, available as free software. It includes features designed for the production of technical and scientific documentation, and is the de-facto-standard for the communication and publication of scientific documents.

There is a couple of online webpages that allow you to create manuscripts, including Overleaf and Papeeria. Both provide a lot of templates (e.g., for APA6 style) that permit formatting your document in accordance with the requirements of journals. Many journals (e.g., Scientific reports) even provide their own template.