This is a simple app using the Conclave API. It is licensed under the Apache 2 license, and therefore you may copy/paste it to act as the basis of your own commercial or open source apps.
Start the host on a Linux system, which will build the enclave and host:
./gradlew host:run
It should print out some info about the started enclave. Then you can use the client to send it strings to reverse:
./gradlew client:run --args="reverse me!"