The application allows you to connect to a Siemens SIMATIC S7-1200.
With this free application you can perform the following tasks:

1.Connect and identify up to 50 networked CPUs
2.Change the CPU operating mode (RUN/STOP)
3.Read CPU and module diagnostic information
4.Monitor and modify variables or tags
5.Flash CPU LEDs for identification

可惜iOS版本需要5.0以上，懒得折腾了