Hi, I suspect that this 'App' was created by someone who lives either South or East of Birmingham. These 'Flat Earth' people, whose highest natural terrain is 800ft in High Wycombe, have no idea what is needed to fly in the hilly areas of Wales, Scotland or anywhere north of Manchester.
In our area of GB any plan involving flying along a pencil line on a chart soon fails upon initial contact with the first Cloud/Mountain combination.
The options are several; Try to squeeze between mountain and cloud; Try to climb over the top (and not into airspace.); Or go around, maybe a detour of 10-30 miles. If none of that works then its a 180 and an early tea.
It is a shame that NATS exclude GA from class A airspace, it compromises our safety by reducing our options. Is there any need to have Class A below 8,000ft? Surely it would be better to have it as Class D, and so we would have some form of radar ATS service as well.