Make a good photo great by using one of my all time favorite apps: Color Thief. This app "steals" the color from another photo (or even a web page) and applies it to the one you choose. That does not sound as freaky cool as the app really is! You have to try it. And I can't believe that you won't be as addicted to it as I am!
Here is an example of a photo I took on the beach in Ventura, CA. Now, I like this photo as is. I LOVE it in its new color permutations. Check this out.
The starfish was lovely in its imperfection, one shortened arm, twirling in the sand. All I did to the original was to optimize it in Snapseed (tune image and details.)
Then I brought it into Color Thief and started zipping through the pix on my Camera Roll (this is a highly addictive part of the process. Like slot machine wheels going past, adding color instead of coins.) These were my favorites.
My all time favorite of the starfish color renditions was this one, which I posted on social media sites. I called it Pirouette.
And now I find out that they have an app for the Mac - oh joy, oh rapture. I'm heading for the app store right now. Oh, and did I mention that of course, it saves full resolution? It doesn't get any better than this.