Create a VCC Seed option

This is already possible in Fritzing albeit a little complicated.

1. Remove all existing copper fill.
2. Clear all ground fill seeds.
3. Use the view from above/below button to view it from the side you want as ground.
4. Use the top layer/both/bottom layer button to only allow work on the ground side.
5. Set your ground seed.
6. Ground fill top/bottom which ever side you are working on.
7. Clear ground fill seeds.
8. Switch view to the opposite side.
9. Switch the top/both/bottom to the opposite side.
10. Set the ground fill seed but this time select your vcc instead of ground
11. Ground fill top/bottom which ever side you are working on.
12. Clear ground fill seeds just to be safe so you can’t accidentally click ground fill.

Now you will have 2 filled side with different seed points.