The standard payment frequency for all recurring payments processed by the Donations app is monthly. With a recent release of Soapbox, if you are using Authorize.net, CyberSource, or PayPal Website Payments Pro as your payment processor, you can override this standard behavior on a form by form basis to accept annual recurring payments instead. If if this enabled, any recurring payment created through that form - whether processed seamlessly on Soapbox via your payment processor or off-site via PayPal Standard - will be setup as an annual recurring transaction.
Happy Soapboxing!