I haven’t used them personally, but there are several mentioned in the replies to this tweet about the MS eBook shutdown: https://twitter.com/rdonoghue/status/1

I haven’t used them personally, but there are several mentioned in the replies to this tweet about the MS eBook shutdown: https://twitter.com/rdonoghue/status/1144011630197522432?s=2 https://twitter.com/rdonoghue/status/1144011630197522432?s=2