QLFits

If you are someone who deals with FITS files regularly, then QLFits might be the software for you. It provides you with the ability to access the FITS header right from your Finder without even having to open the file. This feature in itself is a significant time saver, as you no longer have to open each file to get the information that you need.

Apart from this, QLFits automatically generates an on-the-fly thumbnail along with a preview of the FITS header. What's interesting is that the preview comes with colors, which makes it much easier to read the information. This feature is especially useful when you are dealing with a large number of files, and you need to find specific information quickly.

QLFits also detects ESO keywords, which makes it easier to link the file summary, proposal abstract, and even the weather conditions automatically. This feature not only saves time but also ensures that you have all the information you need in one place.

If you are looking for an even better experience, you may want to consider upgrading to QLFits 2.x.x. Paid users can enter the email address associated with their QLFits account to get the 2.1.1 upgrade for free. Overall, QLFits is an excellent software for anyone who works with FITS files regularly and wants to streamline their workflow.