@LaxusI've done some digging and it appears that the mod works on 4.8 with some of the content still showing locks, however all the content is unlocked. Above 4.8 the mod is not working on ios 13.5 running on both ipad pro 2018 and iphone 6s Uncover jailbreak. My hunch is that something in 4.8.1 broke the mod I can provide screenshots if needed. All later versions of the Calm mod install as normal but do not actually unlock any content.
guide for people having trouble installing calm hack (working on 13.5 uncover jailbreak):
Prerequisites - Apps Manager (https://tigisoftware.com/cydia/) and Appstore++ (https://cokepokes.github.io/) tweaks from Cydia.
1. Install tweaks and this calm mod
2. Navigate to calm in app store
3. long press on install button (open button if already downloaded)
4. Select Upgrade/Downgrade
5. Scroll down and choose 4.8
6. Wait till it fully installs then open the Apps Manager tweak on home screen
7. Navigate to Calm and press Wipe data (if you had calm previously installed it will detect you are downgrading to a lower firmware and crash itself)
8. Open calm app navigate through the start up pages
9. Close the Calm app from multitasking, relaunch it and the mod will work once you resign into iosgods and turn on in the cheat menu
10. Pull down on the page to refresh the app and show the content unlocked
Note: Some content will appeared locked, however it is not actually locked it will still play when you press on it. This version of calm is quite buggy and to navigate through the menu you have to long press on the icons in order for them to register otherwise it opens up the now playing window.
I hope this helps the people who can't figure out how to get it to work in the meantime hopefully Laxus can resolve the issues for true compatibility with 13.5 :).