In RWY for Android, the following steps enable a plan to be 'saved' and accessed later.
Create your plan as normal (see our RWY for Android documentation for help).
When you are finished creating your plan, you need to press the 'Activate Plan' button, then PRESS AND HOLD the Cancel button in the GPS HUD (Right hand Side, bottom row)/ This will exit the plan and store it for later. The plan can now be accused by tapping the 'plan' button in the title bar (right hand side), where a list of plans will reappear.
When exiting plan you wish to keep, always use cancel. Using the 'Delete' function from inside the Plan Menu (the 'i' inside the circle on the Plan Progress window) will not only exit the plan, but delete it entirely.