i-navx is significantly better to use than navionics.
stores waypoints and routes separately.
Can
But is a pain to set up.
Download app - a cost
register with a cloud server called x-traverse - a cost.
The upside is once its all downloaded it stays on your tablet.
Your x-traverse membership is theoretically yearly.
It only ever asks youfor it if you update your software.
ie don't upgrade your software and then you only pay once.