Caesar is a lightweight utility that lets you resize windows in a predefined size.
This application installs a menu on the title bar. From there, you can change the ratio of any type of window to the following options: 640x480, 800x600, and 1024x768. You can also choose another size
Also, if you want to move the window to a specific part of the screen, you can do it here Access the app settings just by clicking the icon in the title bar.
Caesar is a great application for web developers, it allows you to resize a window with a click. It's also useful for screenshots that are frequently used frequently.