That app should update automatically whenever a new release is tagged (see the metadata), but if you look closely at the linked repo the most recent tag is v1.31. It doesn’t look like the project has bothered to tag their last two releases.
It looks like the tag was detected (it was added to the metadata), but the build itself failed.
I’m not entirely sure why it failed though. Its complaining there is no setConnectTimeout method on Android’s HttpUrlConnection (and there isn’t), but there appear to be a few versions of this class floating around. Those methods are present in the version shipped w/ Java. I glanced at UploadThread.java where the error occurs and the imports aren’t explicit (a lot of widcards).
Just for my personal interest: when I fetch the sources given in the related F-Droid entry, what do I have to do to make an Android-App out of it? How has it to be build?
This will depend on the app. In this particular case, for OpenWLANMap, you would need to download the source and open it in eclipse IDE.
EDIT: or import it / convert it into the IDE of your choice.
Also note that you need to download a special library (quote from the readme of the project) :
To build this app libwlocate is required. Either use it as library (.jar to be added to
the project) or set a symlink from
libwlocate/master/android/LocDemo/src/com/vwp/libwlocate/ into
libwlocate/master/android/OWMapAtAndroid/src/com/vwp/ (so that there is a directory
“libwlocate” in folder “src/com/vwp/” afterwards.