What Trusted Execution Environment (TEE) solutions exist for mobile devices?

A trusted execution environment (TEE) provides a way for one to deploy tamper-proof programs on a device. The most prominent example of TEEs seem to be Intel SGX for PCs.

What I wonder is, if there exists an equivalent solution for mobile devices. For example, I want to deploy an arbitrary application on a smartphone that even a malicious OS can’t tamper with. Is there such a solution at the moment?