Overleaf is an online LaTeX and Rich Text collaborative writing and publishing tool. You can use a free version with storage space up to 1GB and you find a whole string of templates for different publishers.
ShareLaTeX is an online and collaborative LaTeX editor. The free version includes only one collaborator.
The journal PLOS Computational Biology has published a series of editorials on scientific skills that are necessary for a scientific career, e.g.
Ten Simple Rules for Better Figures
Find more articles from the Ten Simple Rules collection at http://collections.plos.org/ten-simple-rules.
The University College London offers an interactive self-learning course in Academic Writing in English. This app is availalbe for iOS and Android.
Find more at http://www.ucl.ac.uk/english-usage/apps/awe/index.htm
This blog post by Next Scientist gives you some tips to improve academic writing including 15 typical English grammar goofs: