Gif Viewer is an open source app to visualize and extract frames from GIF files.

After the routine installation, you can optionally associate GIF files to Gif Viewer and by default will open Windows Explorer or File Explorer to browse for your first GIF. Later you can select open from the simple interface. Drag-and-drop is also supported.

Once loaded you can view the frames and scroll through and extract any frame you like. You can also play the GIf to see it in action as well as define the speed in milliseconds.

Finally, the settings allow you to define multiple instances, memory usage, and maximum keyframe reach.

At the end of the day, if all you want to do is view and extract frames from a GIF file, it doesn't get any easier than Gif Viewer.