The iOS file system is in the format of Apple File System (APFS) , Same file system for iOS, iPadOS, MacOS and etc.
All application processes run another the mobile user and can not access outside their application and data directory.
All the phone application are installed under /Applications/ .
All the installed applications are under /var/containers/Bundle/Application/, the application data is stored in a different location (/var/mobile/Containers/Data/Application/).
irons-iPhone:/var/containers/Bundle/Application root# find . -name *.app
./7425A26B-2406-4BD8-A877-AFB149B2AEAE/AltStore.app
./2066F710-CB14-4CA1-9919-3691D39AA172/News.app
./0289B77F-A596-4301-BFBC-F7C1D170EF3C/Measure.app
./F4121B58-3BA1-43E6-93DC-11F40C7DBDC2/VoiceMemos.app
./B86CDE39-2EDB-4071-A387-90F78A096687/Bridge.app
./10253D3E-672C-484F-B1D4-75A115FA5807/OpenVPN.app
./31C92BF5-613A-4878-94EF-4FD55ADF69F0/FaceTime.app
./9B6DB483-7397-40EC-A9B8-BC6C99CAA55A/iSH.app
./0CEFCFF7-7219-4C1B-9912-53D595E5EEEC/MobileCal.app
./6E1FFBD4-D35C-46BB-9F93-3182D9B9D81B/Calculator.app
./867D0507-6413-433A-85E8-6409164BE90A/TestFlight.app
./3BB106B2-73B1-4A7C-9ADC-B18928366484/Weather.app
./72C7F04F-3D99-406B-B6EE-C8F5B42E59DA/Stocks.app
./7537CA7B-A429-4EB7-B130-009115ACD63C/MobileStore.app
./74071982-41C1-4148-9348-A4C6EC9C3FA7/Compass.app
./81A5F40C-1EE8-4BB2-96D4-523DFA51E90F/Books.app
./B57302B2-C15A-42F4-887A-296C01E56702/Tips.app
./11DA4403-0F55-4E46-A499-4B47E208B917/Music.app
./A6FBFA46-4BB8-4AFF-99A7-6A7AC9E2112F/Shortcuts.app
./A8EDDAE4-7D9F-4222-A117-5A4EB1EAAC05/Files.app
./DDFFD3A3-5227-49BE-B436-9BACA3DB72E1/AppleTV.app
./224A143D-9197-4614-838B-D5A54BA4A7F1/Maps.app
./6F92DC5F-D1E3-4C10-B092-09D7F1A133EE/Reminders.app
./1C7855B4-90FA-400C-B59A-1CC9413CC723/Podcasts.app
./083DB6CA-9398-41B8-8667-2ADE54905712/MobileMail.app
./6D84D653-135C-4A00-980B-AFFCABC3C48A/Home.app
./E2511B9C-236C-4F5D-8B9F-94637029665A/MobileNotes.app
./7663E319-7777-4E8C-8C9E-550F22B36A54/Contacts.app
./4675AC88-8E84-44C4-8EB6-840B1AF1844E/AppCenter.ms.app
Using objection