If you dont't want that every time you take a picture with your Android device, it gets instantly uploaded to your Google+ profile, this tutorial's for you.
We will open a random photo taken at day light and add exploding fireworks to it. We will also we will modify the whole picture to make it as realistic as possible, enjoy!
Pixlr is a free and probably the best web based image editor. I will show you how to open and and resize an image, I'm sure you will be impressed how well the web app actually works.