Emulation on iOS

What are your thoughts on the current emulation scene on iOS? Since Apple does not allow emus to be published on the app store, you will have to go through the tough process of either jailbreaking or sideloading with tools such as AltStore.

At the moment I know that Provenance is a frontend for multiple emulators similar to Retroarch, which is really useful considering with a normal apple account you can only side load 3 apps, including AltStore itself. Though I would still love to know other emus available for iOS