Generally the shows are released to the internet (And thus the apps) after the closing credits run on "Live" Broadcast. This applies to both Broadcast TV and Cable/Sat channels.
For NETWORK (not local) you can type the name of the network into the app store and they should all have apps.. I am unimpressed with the ones I have tried but it's been a while and they may have improved them.
For "Local" type the callsign of the station into the app store search.. Same comment.
I'm not impressed by Straming video for the most part.. I do download a couple of shows (one a week plus one a month) for later Chrome Casting,but I either give up quality or it takes hours to download a one hour show. Since these are technical shows where I need to be able to READ hand drawings, I go for quality.