Be sure to include a cover letter when you send an application/post your resume for a job on Symplicity. Include the letter even when the employers does not specify "cover letter" among the required application documents. They don't mention it primarily because they assume you will include a cover letter.
Cover letters tie together the various parts of your application and make the case for why the employer should hire you. Don't miss this opportunity to tell your story and demonstrate your writing skills.