For Android, you have to put it here:
{SdCard}/Android/iFly.GPS/files/iFly/Data/FltPlans/
We need to update our FAQ for this new Android feature.
Also, we should accept the path:
{SdCard}/FltPlans
This is case-sensitive. "fltplans" won't work.
Please let me know if this now works for you.
Please try it again (try Load Flight Plan option), then after it fails to find them, do "Menu => About => Send Bug Report" so that I can see your folder structure.