Version tags should be used only for version specific questions (e.g. problem specific only to that specific Ubuntu version), not just because you're using the version. Since 18.04 is the current LTS release it's very likely that any software which is still maintained would be available for this version. If you have found any software which used to work with older release, but not with 18.04, then edit your question and mention it explicitly. —
pomsky 4 mins ago