Difference between OsmAnd+ and OsmAnd?

What is the Difference between OsmAnd+ and OsmAnd?
both Versions are available on PlayStore.

I don’t particularly like subscriptions so am tending more towards the unlimited version which has monthly map updates compared to hourly (and no contours/nautical info).

Is this your question or your answer?

OsmAnd is the free version with just 3 or 5 cards available and OsmAnd+ is the full version where you can download every card and as much as you like. And if i remember correctly, there are live-updates with the + version.

OsmAnd+ is free as well (on Android)

No, its not. Its 14,99 € right now. https://play.google.com/store/apps/details?id=net.osmand.plus From where do you want to download it for free?

I did donwload my version last year for free.
However, I receive “SALE” pop-up messages reuglarly.

Neither. The user is a spammer that is mixing “vaguely appropriate but meaningless” posts with actual spam. It’s not necessarily an actual human posting the messages, since the content is “sub-Eliza”.

I assume he’s referring to OsmAnd~ (https://f-droid.org/de/packages/net.osmand.plus/)
[edit:] Wrong citation

Updating this thread for current answer as of today: OSMAnd is free and limits you to seven downloaded maps. OSMAnd+ costs $12.49 (USD) and is unlimited.