Addon authoring

[tangerine0469]

I have a really dumb question for you guys... It seems one of the addons I like has not been maintained and if I remember reading correctly it will no longer be maintained. Can I pick up where they left off? I would of course add notes about who made it and simply take credit for keeping it up to date, or is this not allowed? The addon I am speaking of is craftstore. I know i could do it for personal use but it seems to be one that a lot of people liked and would be nice to reintroduce it.