It mostly works
The app mostly works, though you can’t jump to a metre band from the list on the right which would be helpful. There are also some errors in the data, though this seems to be an issue with the database used, rather than with the app itself (an example being Voice of Korea having some frequencies missing). All in all, it’s a useful app and clearer than using most websites, but I think £6.99 is perhaps a bit steep - maybe £3.99 would be better?