Does Mojave need Flip4Mac ?

I don't think the has worked in about five OS releases.

If you go to https://itunes.apple.com/us/app/etrecheck/id1423715984?mt=12 and download EtreCheck report. Then run it and post the report here. We can find anything else that you might want to get rid of.

You can save yourself a bit of time by going to RoaringApps to see if any app is compatible with macOS Mojave, instead of asking "piece-meal" here. Also, you or someone else may have installed these apps, either intentionally or not ... and, whether or not, you will still want to use them will be a personal decision.

If your goal is to free up storage space on your Mac, and especially if you got a used Mac, would be to use Recovery Mode to both completely erase your Mac's system drive, and then, install a "clean" copy of macOS. You can then add any additional apps that you need.