Yes, such adapters are really convenient. I recently bought Celestron NexYZ 3-Axis Universal Smartphone Adapter, and it works great. The coolest feature is three adjustment knobs (X-, Y- and Z-axes), which allow you to precisely align the smartphone camera with the eyepiece. This is especially important if you want clear photos without blur. It also has a durable design – a metal frame and strong polymer. The phone is held securely and does not slip. If you want to avoid shaking altogether, you can connect Bluetooth shutter button. Works with many telescopes, including 1.25″ eyepieces. By the way, if you are looking for alternatives, check out the smartphone telescope adapter – there are also interesting models there.