Answer:
1. The benefits to using a online filter app are
-Smoothing water movement in waterfalls, rivers, oceans, etc.
-Achieving a shallower depth of field in very bright light
-Reducing diffraction (which reduces sharpness) by enabling a larger -aperture
-Making moving objects less apparent or not visible (such as people or cars)
-Introducing blur to convey motion with moving subjects
2. Adobe Photoshop Express. This app provides an amazing amount of features that other apps just don't come close to the other apps I have researched. I've even done some testing on my phone and it appears to be user friendly which basically means even my grandma can use this without having a difficult time.
3. I would choose the apps filters because it has more options to choose from. The only time I would use the accessory filters would be if i'm going to something quick and simple. Since i'm more of a perfectionist I love to use the apps filters.