Tips for image manipulation

Hi everybody!
Who where has some good tips for me when it comes to image manipulation. What i want to creat is the following:

  1. You make a photo or choose one from your phone.
  2. Now you can add a watermark, and text on it.
  3. You can also blur a part of the image using something like this: http://blurjs.com/
  4. Now can save the (merged) image to your phone.

It would be awesome if you can help me with some insights how you would create this.

Thank you!