What smartphone are you using? I bought two of these DSP-LF and both work great with my iOS devices but neither work with my Android 10 devices. With the Android, as soon as I click on the identifier in the app, it crashes.
Also, the Android app hasn't been updated in nearly 2 years which means it was released 3 generations of Android in the past. Not a good thing.
If they were to go the open source route, or even just documented the serial commands, we could build our own interfaces.