Android / Chromebook Disclaimer
Due to a design change by Google in 2016, DrawBridge filtering is limited on stock Android devices. The Android Operating System doesn't trust the SSL/TLS certificate required by DrawBridge filtering (more information here). Because of this same Certificate issue, we are also not able to filter Chromebooks (ChromeOS).
We can generally lock down an Android smartphone to be a Talk and Text device. But apps that need a data connection (including Google apps such as Maps and Gmail) may work only partially, or may fail in a completely closed position, or may fail open (unfiltered). We can bypass some such apps from DrawBridge filtering (a billable customization) but that may not be desirable for all apps. A notable exception is browser apps. Android mobile browsers generally work well with DrawBridge filtering.
The Vision Android phone is one solution to this certificate issue and is fully compatible with DrawBridge filtering.