Boxing manager for IOS is a good manager sim and perhaps the best boxing game currently out. It is sort of what I hoped TBCB would turn into.
TBCB has a better boxing engine. Boxing manager is better than everything else and your matches actually have context without you having to do all the work yourself.
And it keeps getting updates.
And there is talk of a PC version Kickstarter being launched at some point.
https://theboxingmanagergame.com/