Step 1
Open Shortcuts app
Step 2
Add new shortcut
Step 3
Tap Add Action button
Step 4
Select Scripting option
Step 5
Choose Open App
Step 6
Select the app you want to add
Step 7
Click on More button
Step 8
Tap on Add to Home Screen
Step 9
Type the name and tap on the app icon
Step 10
Select the Choose Photo option
Step 11
Choose your icon and tap on Add
Step 12
Hooray! Custom app icon should be on home screen