Adobe Express
Your all-in-one AI content creation app for making stunning thumbnails, social posts, images, videos, flyers, and more. Create content seamlessly with syncing across computer and mobile devices, so you can work where ever you are. With a free option as well as a standalone paid version or as part of the Adobe Creative Cloud.
Canva
Canva is a cloud-based graphic design tool used to create Thumbnails but also so much more, on-brand marketing content, sales presentations and videos. Thats right you can even edit videos in Canva. Canva has been designed for ease of use, getting the functionality of some of the more in depth graphics apps without the learning curve. Canva is available in both a Free and Paid Version