Prewriting and checking your work before you submit
As with any written submission, it is expected that you proofread and spellcheck your work before you submit. If you are using Microsoft Word or Google Docs to write then that should be easy. Make sure your punctuation and capitalization are correct and you are not writing a submission like it is a text message. (Keep in mind that Microsoft Word has various features for checking grammar, context, and spelling as well.) Most assignments allow for file uploads so you can upload Word Docs and PDF files. If you use Google Docs, click on File-->Download as...-->Choose PDF.
What those tools do not always catch are stylistic elements that might need fixing. The step after you have proofread your paper is to copy/paste your text into HemingwayApp.
Step 1: Use hemingwayapp.com and paste your submission.
Step 2: Review problematic areas that are identified and clean up your draft right in the app.
Step 3: Copy and paste your new submission into your assignment.