Timely post as I've been seeing the same problem with my iphone as well as others. I don't normally use the app as I prefer the remote but for the most part it seems to connect OK on my home layout (may take a few tries).
A few weeks ago I went to a temporary Christmas display layout to help them set up their wifi and experienced connection problems. One fellow had the free app and connected with no problem. It took me several tries to connect. A third fellow took about six or seven tries. We all checked our iphone setting screen to make sure the MTH wifi was selected. Why we had so much trouble connecting I don't know.
A few days later our local club had a show. When I got there some of the club members were getting the NO WIU/TIU Found error message. The correct wifi network was selected but still kept getting the NO WIU/TIU Found message. Eventually we had to run one train with a remote. Later some additional members came in and had the same problem. I powered down the TIU and WIFI units, powered back up and then was able to get the app to connect and work properly. The next day I tried to run an MTH engine and couldn't get my phone to connect. Gave up and used a remote.
Over the course of less then a week I've seen many connection failures and NO WIU/TIU found issues involving different TIU's WIU's, iphones, and users. I don't see any pattern and its getting frustrating. I hate to recommend to so many people they need to delete and reload the app and then reload all their engines. If that's the only way that's what will need to be done but there seems there is a fundamental issue with the app and WIU that needs to be addressed. Since neither the app or WIU has been updated in some time I wonder if they are still compatible with all the iphone operating system updates that seem to come out every few months.
Anyhow, what's the difference between these two error messages. To me they are the same.
"Connection Failure"
"No TIU/WIUs Found"
Ken
