Grammarly is an online spelling and grammar checker that is easy to use and simple to install as a free browser extension on either Chrome or Safari. The service flags grammar or spelling issues and suggests alternatives while explaining the reasoning behind its suggestions. Like most products of this kind, there is a free browser extension, which corrects about 150 types of grammar and spelling errors, and a premium version that will spot and correct more than 250 kinds of errors. Most people find that the free version is sufficient. However, those who are writing professionally or particularly concerned with their grammar may want to upgrade to the pay version in order to access the full service. Once installed and an account is created, Grammarly automatically becomes active during all your online writing, including email and social media.