Photo Room is one of the best app to edit photos and images easily.
Blend images, make transparent background, change color and a lot more to do.
Here are some filters and effects:

• Blend Images : blend images as many as you want
• Make transparent background
• Flip image
• Blur : Make a blury image
• Brightness, Contrast, White balance, Exposure, Hue Saturation, Negative, Temperature and Tint, Solarize, Sharpness
• Swap Color : Change color of any part of image
• Warping
• Mirror, Magic Pen, Sketch, Lomo, HDR, Fog, Cartoon,…
  and a lot of filters and effects that make your photo and image more beautiful and fun