Canva is a free and simple graphic design tool which can be great for creating graphics for your website, social media channels, sermon slideshows and other church materials. All you need to do to get started is sign up for an account at canva.com and then you will be able to start designing.
Here is a link to Canva's Help Center where you can search for different "how-to" articles: Link
View a list of your Tithe.ly Sites image and photo dimensions here.
You can quickly re-size, crop or edit your photos easily. No apps or plugins required with Canva's Online Photo Editor
Crop and resize: With their simple drag-and-drop controls, you can crop and resize your photo in mere seconds. You can also choose the pixel dimensions you want, or change the aspect ratio. All in a few clicks.
Check it out Canva's Free Online Photo Editor