EPUB Editor/Reader

I use the Sigil EPUB editor, a versatile program for all your editing needs. It makes it fairly simple to edit text, HTML and CSS; anchor/link notes; edit metadata; validate EPUBs for compatibility and finalization; and literally a bunch of other stuff. A great editing tool in general.

As for reading, I use the calibre e-reader (I don’t check outside of Sigil too often to be honest). Since I tend to use a lot of custom fonts and later CSS properties (for the tables and the like) I recommend using calibre since some other readers might not support them fully. It’s not a light program but has a lot of features like the ability to convert between EPUB/MOBI/PDF/TXT files, as well as other formats, and is a convenient way to organize a lot of e-books (though I’m not too fond of the save location format, but that doesn’t really matter for most people and isn’t really a big deal). I don’t think there have been any problems with physical e-readers.

I also use the GIMP program to edit images. A solid image editor I mainly use for cropping, rendering and getting rid of unwanted text (though the particular process is time consuming depending on how detailed the image is).