In September 2018 the Essential and Premium plans were introduced and are our only two official subscription plans. However, existing customers who signed up prior to this will be on either Lite, Standard, Pro or Plus plans.
While we continue to support users on the old plans, new features that are rolled out will only be available on Premium or Essential.
It is possible to migrate to either Essential or Premium at any time, by switching to a new plan under "Your Account" in the Store Admin.
See New subscription plans help article for more information about the changes in the new plans.