Next feature update to Campaign Manager is taking some time, but it's a big one - a built-in map editor!
It supports typical image creation functions such as layers and basic drawing tools. However, it also supports painting/spray-painting a large library of textures (grass, dirt, stone, lava, etc) and easily adding a grid overlay.
The drawing tools will continue to expand along with the texture assets. Stay tuned for its releases!
You can download Campaign Manager from: