I am quite confident MyRoteApp is/will be the best navigator software but I really wonder if a tablet exists for it. The mandatory features are:
-Waterproof and rugged.
-Visible in sunshine.
-With a touch-screen able to detect gloved fingers
-7-8" screen, no more.
A professional mount with power input is also a must!
As far as I know, such a device doesn't exist, so, how am I supposed to abandon my hated TomTom?
I am using a Blackview BV8000 5" rugged waterproof phone, daylight readability is good and quite big enough for navigating. A stubby stylus on a cord allows for use with gloves.
For planning, I use a 10" tablet which can be in a waterproof case if needed.
You could try the 'Sony Xperia Z3 tablet compact' 8" waterproof, I don't know any rugged mount for it though.