No nonsense, affordable astro software that just works.
The Filter module allows for the modification of features in the image by their colour by simply clicking on them.
Central to the module, is the 'Digital Development' parameter, which controls the strength of the development and resulting stretch.
The Color module allows for various ways to calibrate the image, including by star field, galaxy sampling and - unique to StarTools - the MaxRGB calibration view.
You can convert everything you see to a format you find convenient. Give it a try!