Leadnav for iphone/ipad instructions/maps

So i want to use my phone/ipad for offline gps. I purchased Leadnav app because it seemed like it would do the things I want. ( pretty much work as a gps) The only thing is that I dont know how to use it.
Does anyone else use this?
Is there an instruction manual?
Can I download maps with way-points already in place?
Is it the best app to replace a gps.