Puede utilizar Inkscape (dibujo vectorial) y Gimp (edición de mapa de bits). Son software que se pueden descargar y usar libremente.
La configuración de la interfase es distinta a los programas de Adobe antes sugeridos. Los de Adobe son con licencia comercial o con fines educativos, según desee hacer la suscripción. No son gratuitos.
Inscape y Gimp son muy buenos, pero eso dependerá de la destreza en el manejo de la herramienta.
Creating an original graphical abstract can be challenging. You can use Mind the Graph (https://mindthegraph.com) to create and boost your work impact! Also, there are some guidelines in the blog that connect you with the necessary steps: https://mindthegraph.com/blog
Misbah Ghazanfar, there are several alternatives to create graphical abstracts such as Cytospace, Gimp, ImageMagick, ImaheJ, Inkspace, and R. Some of these are basic and simple to use while others have more drawing tools and require more effort. As Sandra Mariela Cadelago wrote, Gimp and Inkscape are two good open-source, semi-professional programs. In any case, choosing one that will work for you will depend on your needs. You can find information, URLs, and tips on https://www.enago.com/academy/which-tools-should-you-use-to-design-quality-images-for-research-papers/.
You can use Inkscape. It is a free and open-source vector graphics editor for GNU/Linux, Windows and macOS X. It offers a rich set of features and is widely used for both artistic and technical illustrations such as cartoons, clip art, logos, typography, diagramming and flowcharting. It uses vector graphics to allow for sharp printouts and renderings at unlimited resolution and is not bound to a fixed number of pixels like raster graphics.
Go to: https://inkscape.org/
For editing Images and getting the desired output from Inkscape use
Misbah Ghazanfar PowerPoint is the best option. /you can also try some advanced software, Inkscape, Photoshop, and Adobe Illustrators. You can also improve your graphical abstract by using other free online software: