It looks like several reddit users have unearthed the next version of the TaiG jailbreak for iOS 8.3. Several users have posted screenshots of the tool, which is said to fix the Cydia Substrate issues, iTunes issues, etc.
I’ve tested the untether myself, and I can confirm that it works. Cydia Substrate now works, and jailbreak tweaks that are compatible with iOS 8.3 now work.
Note: TaiG has warned users not to use this release, as it is still in testing. Proceed at your own risk.
The untether must be installed with a tool like iFile or via SSH. We’ll have a full tutorial shortly. If you’ve yet to jailbreak, you can use the TaiG 2.1 tool instead.
Have you tried the TaiG 2.1 update yet? What has your experience been like with it? Are you happy to have jailbreak tweaks supported by Cydia Substrate back on your device?