How can I get a subscription?

After starting Audio Memos, press the "i" shaped button under the list of memos, then press "Subscription". You will see a list of subscriptions that can be bought to enhance Audio Memos. To start a subscription, press its price, then enter your Apple ID credentials to confirm your purchase.

Subscriptions vary by duration and by the features they enabled. The "Pro+" subscriptions give access to a few more features than the "Pro" subscriptions (like encryption settings and higher recording sample rates).