Adobe Photoshop is amazing and very powerful. But unless you are in the business of producing commercial output that makes you money, it is an overkill, and frankly too expensive.
But what are the alternatives ? I would say On1's PhotoRaw 2018.x is the best out there for adjusting photos for optimum output. The cost of PhotoRaw is also far more affordable.
And if you are really penniless, why not give pixlr a whirl. It's really quite good for a web-app.
