I think the majority of them are known or not surpsiring at all, but there are a few ones that are interseting, like TikTok's hacking* of App Store title length.
* I know it isn't hacking, but I couldn't find a better word?
> There was a secret in the app store. You could make the application name really really long. And the search engine on the App Store gives more weight to the application name rather than the keybookwords defined. So we put a really long application name, "make awesome music videos with all kinds of effects for Instagram, Facebook, Messenger”. And then traffic came from the search engine. That's how we initially got started.
Longer app length = more random/other stuff matches = more views
* I know it isn't hacking, but I couldn't find a better word?