Used this plugin on a client site for a while. It seemed to work pretty well (occasional plugin conflicts but mostly smooth sailing) before they did an update that required you to get a trial and account with hitshipo. Once that happened, the plugin just randomly stopped working. I assumed because of new account thing.
Wouldn't let me troubleshoot mode or save settings after that update unless I gave an email to do a free trial. No more "save" button.
Tried to find out if it was still possible to use the "free" features of the plugin without signing up for the trial on the forum. One support person told me that the features we wanted were free, but features like shipping labels weren't, so if we wanted those we'd need to pay. Didn't need those. They sent me to an email to continue discussing. Explained myself again to that new support person, and they told me we actually couldn't use it at all without a subscription. So kind of confusing mixed feedback for me.
Okay, well fast forward, client decided to buy a subscription on hitshipo website. Gave me the integration key. When I went into the plugin to find a place to put the pro version integration key, there was none. Just that button for a free trial. Tried to add the client's email that they signed up with. Error- already in system. Used my email to start a trial hoping a spot to activate a paid plan might show up afterwards. Nothing. Couldn't change what account it was connected to anywhere within the actual plugin or in the hitshipo app settings. So if you're going to sign up with them, I'd say make sure to do it with your email directly through the plugin trial button rather than on their site, or it seems like it will be a pain to switch it to a different account.
We had all kinds of problems with it conflicting with things on the site once activated with the subscription. When it was active, it broke a ton of stuff in our theme (Aoki) making the site mostly unusable, and it made it so payments through the WooCommerce PayPal Payments plugin wouldn't complete. So be sure to test a full purchase if you have that specific paypal plugin--not entirely sure it's compatible with it. Probably fine for pretty simple sites, but we had a lot of issues.