Dev:Updating extensions for iOS 15/16

Let's collect knowledge like we did with iOS 14, iOS 13, iOS 12, iOS 11, iOS 10, iOS 9, iOS 8 and iOS 7 – paste in your notes and share what you've learned, and somebody else will organize it later. :) If you want to ask questions and share tips over chat with other developers, see How to use IRC for how to connect to #theos and #iphonedev.

Developing tweaks for the palera1n tethered iOS 15.x JB
This jailbreak is primarily a developer jailbreak and has certain restrictions.

Procursus: New Signing Requirements
iOS 15.0+ requires DER encoding of the entitlements, as such it is required that all tweaks are signed with an updated. iOS 15.1+ adds a requirement on hash agility, added in  version   which can be found here.

SBHIconGridSizeClassSizes
This class is responsible for icon grid constraints.

in all arguments of methods and functions is now passed via pointer, instead of being passed as a raw struct.

You can write code that supports both versions like so: