I purchased the "Variable product" add-on back in 2013, and would like to update it so it works with the latest WooCommerce.
About 4 weeks ago, I've sent the author several e-mails with my original receipt asking for an updated version. Up until today I haven't received ANY reply whatsoever. First I thought that maybe my e-mail didn't get through, so I've sent another e-mail (3 weeks ago).
This time with an e-mail tracking code: Within a few hours, the plugin author has opened my e-mail twice. So the e-mail definitely works... but like I said: no response whatsoever.
Morale of the story:
If you'd like to keep your plugins up-to-date without paying every time, you'd better go elsewhere.