Classic Munro days, hand-picked. Distance, climb and time are rough estimates that allow for a walk in from the road; check the route on a map before you go.
Classic rounds are hand-picked. Mapped routes come from OpenStreetMap, where volunteers and groups like the National Trust record walking routes. A route counts a Wainwright if it passes within 60 m of the summit. Distance and climb are worked out from height data; times use Naismith's rule (5 km an hour plus an hour per 600 m of climb) and run up to a third longer to allow for breaks. GPX files save inside a .zip: unzip and import the .gpx into AllTrails, OS Maps or another app. Walks drop off this list once you've done every Wainwright on them.
None of these apps let other apps read your activities directly, so a GPX file is the way in. Menu names move around between app versions.