A free app for Android, by Ryoichi Fukugawa.
Photo Resizer – resize image is an application that lets you easily resize your photos. With a simple design and user interface, it is extremely easy to use. Just tap the image you want to resize, choose the new size, and save it. You can also use the same image to generate different resolutions.
There are a lot of options when it comes to selecting the new size. You can choose between two main options: percentage and fixed. The first one lets you resize the image by a certain percentage, and the second one lets you choose the fixed size. Both of them are very useful, so you will not have to change the size of the photo by using the fixed option.