Though Photoshop Touch doesn't contain a dedicated polarizing filter, you can try to simulate one using an additional layer and a few tweaks.
Step 1: Open the image that needs corrected
Step 2: Duplicate the layer. With the duplicate layer still selected, choose Adjustments->Black&White so that the image will turn black and white
Step 3: From the Effects apply the Gaussian Blur so that the desaturated layer will become slightly blurred
Step 4: From the Adjustments chose Invert so that the layer will be altered so that the dark spots become light and vice-versa.
Step 5: Apply an overlay blend mode to the selected layer
Step 6: Again from the Adjustments choose Level, which allows you to adjust the light and color levels of the desaturated layer that is currently overlaid on the main image. Slide the levels sliders around while monitoring the image
This worked very well.