I choose Travis CI in the end. In brief, I merely want CI service to build, run tests, calculate test coverages and deploy to iTunes Connect for me, get rid of these repeating handcrafted works. CI is there to helps, automatically and remotely.
Hence, setting up and maintaining a Jenkin server takes too much effort.
Sign up Travis CI, GitHub project integration, Enable repository for testing.
You know what I mean.
It's all done.