To edit an image, open the app and tap the thumbnail of the image you wish to edit.
To apply presets to your image, tap the adjustments icon (the slider symbol, second icon from left at the bottom of the screen). The first preset you see is considered the original/no preset applied. You can tap on this preset at anytime to revert back to your original image. NOTE: You can only edit / select one image at a time to edit.
Tap the image you wish to edit and tap the edit icon.
Tap on a preset you wish to use, and tap on the same preset to choose the strength of the preset. Tap on the √ to confirm your adjustment for the preset intensity.
Tap on to access your toolkit.
Here you can use the toolkit items to fine tune your image. If you wish to see more toolkit items, swipe to the right on the toolkit at the bottom of the screen.
After you have completed your edits, tap "Save" to save your edits.