We've seen several users over time try to scrape the bottom of the barrel to solve that and it has not gone well. Custom Android builds, no-name hardware, etc. have turned out to be the cause of multiple issues we've seen in support. If you want to go the Android route, use a high quality Android build (Google, Samsung) with a popular Android device (Nexus, Tab, G6).
We do not currently customize the app for Amazon's app store. It's likely possible to run it anyway via sideload, but we do not test that so I don't recommend it.
A new option we introduced last week is to use Apple TV 4. The caveat there is that if you want to use it as Simple Hub, the app must always be running as the foreground app, so you would want a dedicated Apple TV for that purpose. Figure an Apple TV 4 is $149, Simple Hub for Apple TV is $19, and Simple Hub License is $49.99. For around $220 therefore, you can put together a non-Android solution. That's then your Simple Hub, don't plan on using it as your Apple TV. You then need to make sure to accept software updates and maintain the Apple TV over time. If there is a power outage, you need to start the app manually (or use a UPS).
Simple Hub itself therefore will be simplest for most users as it auto-updates, auto-starts, all automatically. I would strongly recommend Simple Hub for Mac, iOS, and Apple TV with a Simple Hub License over any Android device. Certainly, for users with an appropriate Mac that is running all the time, Simple Hub for Mac is also a great option, but is also much more expensive as a starting point of course.
Thank you.