So one of the main REASONS of a polarizer in landscape photography is the clouds have more depth & texture making the photograph more interesting to the viewer.
An “app” can’t do this because you have to have the ‘original photograph data’ for an ‘App’ program to use & only a real polarizing filter can give you that. HDR apps come close but are not the same thing.

So while the photograph is not very interesting, the clouds are very expressive. With a circular polarizer you just dial it in.

As you can see, those clouds add a very nice “dramatic” environment to the fountain shot. By using a lower shutter speed I added a ‘slight’ motion to the water squirting in the fountain. Your polarizer will drop a half to full f/stop for the darkening effect.
Also get a “good Glass” polarizing filter, the polarizer just like neutral density filters will cause color cast changes. I have some plastic graduated neutral density filters that have a very red to purple shift. Very nice for sunset or sunrise photos but I am careful about their use & aware of that color shift.

I do work my images in Lightroom, but the polarizer allowed me to dial in the clouds for this photo and still have the plants & flowers to be bright enough for contrasting colors to those clouds.

And a couple minutes later on the other side of the river, I dial in the clouds which also brings the glare off the river down nicely.
So yes, I recommend that you keep a polarizer in your kit and at least step down rings for different lenses if you carry several lenses.
What a polarizer does is not able to have a computer “app” do, the computing power to design in “Details” that the camera RAW or other file format did not capture “in the original photo” is going to be immense.
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