@pixelpaperyarn Read them all the time, as a fair proportion of your other responses have mentioned, it is easier to carry several thousand ebooks than their print equivalents.
Though as someone else said, I read e-books not e-magazines.
format: epub2, or epub3 (that more often than not I'll convert to epub2).
apps: FBReader & Moon Reader+ on Android.
sites: Amazon {I convert the Mobi / AZW3 files to epub2}.