Yes, there is a range of accessories for different styles of fishing.
For shore anglers, a Smartphone Mount is a great option to mount your smartphone to your rod so that you wouldn't need to hold your phone.
For boat anglers, the Flexible Arm lets you mount your smart sonar to your kayak or boat, so it can constantly take readings while you paddle which is perfect for bathymetric mapping.
During ice fishing, sustaining battery life could be crucial. A special smartphone Winter Case fits both your phone and an external battery, and protects them from cold temperatures.
And the Night Cover is great for night fishing and low visibility conditions.
Full list of accessories can be found on https://deepersonar.com