The Android app Soviet Military Maps, cycle layer shows contour lines (works in USA, I do not know about other countries). Even when you specify feet for units, the topo lines appear to be metric. I would never want to plan a route with that type of map on a small tablet or phone, but it did come in handy when I rode part of teh Pacific Coast route so that I knew what the next day would be like and where the biggest worst hills would be.

If you have not worked with topo maps before, it can take some time to get used to them. But after a while you can look at a map and know if ithe grade is going to be tough or not.