On mobile, there are a million editors, the majority of which are pretty shit and limit a person's ability to control the exported outcome.
Personally, I use Photoshop Express on mobile, but that is only if I need to. I really dislike having to use mobile apps for things because there is always a delay in the app opening - yes I hate load screens. On top of that, I don't tend to use images on mobile anyway, the only reason I would edit or do anything with an image is that I need to use it for a post.
So most of what I do is on PC as it is, and maybe if that changes I will optimize a mobile workflow. Right now I don't need to and will happily ignore doing anything other than read and send a text on my phone.
Portable Editors
It is surprisingly hard to find more full-featured and convenient editors for browsers though. Most of these mobile apps also share the same underlying editor interface as it is, but that company does not readily provide a browser option.
I guess it is because we install things like Gimp etc, but they also want you to install their shit apps to edit your shit photos of all your shit memories and post it on your shitgram to feel rather shitty.
One option that is convenient might be Canva, really a great product to just get things done but when it comes to image editing has quite a few shortcomings.
So here are two zero install options for editing your images and not having to deal with installing trash that will tempt you to constantly put family photos together as though those people actually like you.
Edit.photo is easy to remember and simple to use. It has a very app like feel and all the settings are similar to what you would get in these apps anyway. I suspect because their parent company is exactly like the one I mentioned that provide the backend for any dev to slap a logo on.
The benefit is now you have that simple interface to quickly edit and enhance images in the browser and when your done just close the tab.
No hassle. They also boast no adverts etc but really if you are not using brave to block adverts what are you doing with your life? Also who cares about adverts.
Another is Photopea, and this one is more for the Photoshop experience. It has a full-featured photoshop interface and even many of the shortcuts are the same.
For something you just open a tab and import an image to it is ridiculously powerful.
So frankly for your word over photo and slight colour change half arse cover image, photopea is overkill.
It is overkill in the browser though, no loading screens or bullshit restrictions on what formats you can export. That is a win in any book.
Side Note
The one thing you will notice is that these expect you to upload an image, and really what I find odd is how many people don't.
It might be a bit hypocritical since on @Dreemport I just expect people to link a cover image to display with their submissions but this comes from the fact that you wrote a post, which is stored on a blog, which has a image already...
Get the point?
Now many people tend to use links directly to websites which store images, and places like Tenor, Giphy, and Unsplash actually welcome that since it allows for analytics.
However places like Pixabay, Pexels and probably some others do not and "Hotlinking" is actually a frowned upon thing. For the most part it uses that sites bandwidth, so they do not want millions of "downloads" occurring when it means the people are not even visiting their site.
So the point is, if you intend to use it in your blog, think about whether you should rather have it downloaded then uploaded and the blog then stores the image for you.
If the sites you are "hotlinking" from removes or refuses the connection your images will not display anyway.