I downloaded Red Waypoint on the Samsung 8. When sitting down beforehand testing it by entering different missions it worked fine. When out on the beach on Sunday where the internet signal was relatively low, it was basically impossible to plan a mission 'off-line' again. I wanted to test the software with my Spark at that stage.
Will try again, but in an open area where recovery would be easier if necessary.
I am still very new to the business and are still building confidence.