SteemPeak allows you to add users and tags to a favourites list for easy feed sorting. You don't even have to follow someone to make them a favourite.

You can also create custom lists to add users too (like Twitter lists) and so then you can select a list when viewing your feed, and only posts from the users in your chosen list will show up in your feed.

Lists are similar to favourites - basically they expand on the ways to customise your feed!

SteemPeak also allow you to bookmark posts which has come in handy for me many times.

SteemPeak #1 - before you write suggestions for the suggestion box, give SteemPeak a whirl ;)

I do have a post about it if you're interested :)