TetherMe Store is in Beta.
As of October 14, 2019
TetherMe on A12 works with libsubstition 0.0.13+ available with Unc0ver 3.7.0~b2+
As of August 28, 2019
The TetherMe store is in Beta
You can buy a license for all jailbroken versions by following the link above and installing a repo via the link that will appear when you have a purchase associated with your account. You are required to create an account to track your licenses. I don't use your personal information for anything.