SimpleExtManager Beta

This is a beta test build of the MV3 compatible version of SimpleExtManager. Depreciated MV2 SimpleExtManager: https://chromewebstore.google.com/detail/simpleextmanager/kniehgiejgnnpgojkdhhjbgbllnfkfdk?pli=1 The plan is for this version to be updated to the one linked above after it exits beta. Then this entry will be hidden or deleted. Also do note that the MV3 versions will NOT carryover past MV2 settings and memory as they have incompatible storage APIs.