I made a little program that we can send to our customers to read/write tags in the event that they are having trouble. We can use it to help them troubleshoot, or make adjustments without having to send service techs out.
A while back a customer started running a different product on their machine which exposed an issue with timer based filter we had on a sensor. We had nobody available to send out to help them at the time, so we sent them this tool and they could adjust the timer preset.
I also added the ability to read multiple tags at once (the lower text box). If we need to know the values of multiple tags, we just send them a text file that lists the tags. They drag and drop it into the text box and it will read them and display the tag read and their values.
Not the prettiest, but gets the job done. There are other things that it does, but I figure this is the only thing that anymore might care about.