Stacking of your images is the easy part, with many quality, free apps available.
But post-processing is where astrophotographers make their hard-won data really count.
StarTools lets you push your signal harder, with unrivalled fidelity.
StarTools keeps a detailed log of what modules and parameters you used.
The Heal module was created to provide a means of substituting unwanted pixels in an neutral way.
There is no one perfect solution, but rather a range of approximations to the "perfect" solution.
You can convert everything you see to a format you find convenient. Give it a try!