ReadingPlan can track progress in multiple plans simultaneously -- just select another plan and carry on as usual. But what if you're sharing a device with someone, and you both want to read the same plan? That's easy too, but first you have to make a copy of the plan.
Tap the Settings icon 
, then Reading Plan.
Tap Edit, then the row for plan you want to copy. The
Edit Reading Plan screen will open. Edit the plan name
as desired, then tap Done and Done
again. If the plan you want to duplicate is one of the default plans, tap Restore Defaults
to install a new copy. Otherwise tap View Available Plans and download the plan again.
(You can rename this copy, too, if you like.) You will now be able to
configure the plans and track progress independently, on the same device.