At GSA the most important aim with academic writing is to successfully communicate your arguments and ideas in response to assignments or self initiated research and projects. However there is an expectation that your writing is understandable, has structure, and that written assignments have been appropriately reviewed and edited prior to submission.
Grammarly is a free app that not only provides spell checking, it also makes suggestions for appropriate adjectives, subject verb agreement and will make suggestions for word order. When you make a mistake, Grammarly will highlight the wrong word, and will offer an explanation of the grammatical issue.
Grammarly also has an add-in feature so it can be used with Word documents. More information can be found on the Grammarly website here