A free program for Android, by Giang Nguyễn.

A simple and useful tool for erasing images is what the Magic Eraser app does. It enables you to retouch your photos, eliminate undesired persons and objects, and clean up text, logos, and watermarks from images. Any undesirable content in images can be marked, and then with a single touch, it can be eliminated.

This app is also very easy to use. Just pick a picture you want to edit, determine which red-marked items you want to eliminate, then to easily retouch or remove unwanted objects, click the process button. After that, you can now save or send it to your contacts.