Sideloading APK- Minimum Android version?

I was able to sideload the apk on to a couple new phones and also a cheapo Fire tablet. I am using these devices and casting the screen to a Chromecast. The phones work great, and the Fire tab is ok but it doesnt cast perfect as I get some pixelation. I wanted to put it on one of my old Galaxy S5s and leave them permanently casting my taplist, and one running Android 4.4.3 wouldnt even install the apk, and the other one with newer OS installed fine, but when I open the app it just stays at the Connecting screen and never connects.

Is there a minimum OS they need? I realize this is really for the Fire Stick, but not sure if there was a minimum or not. And any idea why the one S5 just sits at “Connecting” indefinitely?

Minimum SDK version is 22 aka 5.1 aka Lollipop. I am not certain offhand, but I think I rely on some platform changes that didn’t really stabilize until then — and backporting for earlier compatibility isn’t a huge priority compared to some other things, unfortunately…

Not sure — you could check adb logcat logs and see if anything stands out.