Were you aware that the Android app FiLMiC Pro is compatible with the Smooth 4? It costs $19.99 at the Play Store. It might be a better software than the oem Zhiyun ZY Play although it is pretty pricey. I believe that they have a demo version of it before you buy it.
Poutinemaster wrote: ↑ I have this. I m using it with my P20 Pro. You are right, the hardware is excellent, but the software is not that solid. It improved since the launch of this, but it is lacking some features and stability (has a hard time to follow targets, response can be slow,...) . Often, I just turn on the device and use the stabilizer itself without using their software. Overall, I rate it 3.5/5. For 100$ it is good, when time will come to get something different, I will likely look somewhere else.