And also remember that both IOS and Android (and Tower, Mission Planner and APM2) depend on Arducopter, DroneKit, Linux Kernel, Gstreamer, Mavlink, PX4 and a lot of other code.
Solo is a very complex software environment with quite a few CPUs running various real time OS components.
Artoo:
An Stm32 runs the user interface to the sticks etc.
An iMx6solo runs Yocto linux with real time kernel extensions runs the video receive, HDMI video output and WiFi interface to the tablet/phone.
Solo:
PixHawk has an Stm32 as well and runs NuttX a real tome OS that runs Arducopter as an application
An iMx6solo runs Yocto linux with real time kernel extensions runs the video acquire/encode/transmit and the WiFi interface to the Controller.
Gimbal:
3 TMS320 DSP chips, one for each axis run "god knows what".
There are lots of other software components as well in addition to the above.
Bugs abound in both the beta and released code. It's just the nature of software.