I’m a big fan and regular user of Adobe Photoshop and Adobe Illustrator. Still on some occasions/places you don’t have this software and you don’t want to buy it right then. There is an solution for this problem: it’s “OpenSource software”, you can use it freely and you can install it on your machine very easy.The only problem is that you will have to find out how the program works and look for the regular tasks like cropping or resizing. Still nowadays you can use a PC or Mac without any puchase of any software. And this is something that will grow even more in the following years.
The program that I found for doing the same tasks as in Photoshop is Gimp. The program that I found for Illustrator is Inkscape.
The only disadvantage that I found in Gimp was that in Gimp the Windows are not grouped in one taskbar button but have a button for every window that you open. Maybe this is something they will adjust in the future.