Hi,
trying to install on a 2nd gen Fire stick with OS 5.2.9.5
Downloaded https://f-droid.org/F-Droid.apk and trying to install it it says error parsing package
Do I need an older version of the client? Which one?
When trying to install the same apk by adb shell pm install it says
Failure INSTALL_FAILED_INVALID_URI
Trying the pm install command with the full path to the apk gets me a little further:
It says install failed older sdk now
Go backwards… Running on old Android versions | F-Droid - Free and Open Source Android App Repository
Works, the fire stick has something like Android 5.1. but still some very useful apps are compatible.
Using the F-Droid client with the remote is pretty hard, resorted to ScrcpyForAndroid - IzzyOnDroid F-Droid Repository
IzzyOnDroid v0.14 can be obtained from IzzyOnDroid (unofficial) - IzzyOnDroid F-Droid Repository
One more issue, have installed the F-Droid 1.15.6 client which works on that device but enabling F-Droid Archive repo is a problem.
I have toggled it enabled but apparently it still isn’t enabled. When I tap the line with the F-Droid Archive repo to display the details of the repo it shows a QR code and says “Diese Paketquelle wurde noch nicht verwendet. Um … muß sie aktiviert werden”.. as far as my German goes it means that repo wasn’t used yet and must be activated. Just how do I activate it? The toggle is on
Why do you have the language to German if you can’t read it? 
You need to look at the notification, to see Archive index being downloaded first…
But, with devices with lower than 1.5Gb RAM that index might fail to download 
I can read German and didn’t set the language myself but helping someone. The problem with many languages is the translation is sometimes misleading.
The Fire Stick appears to have 1GB of RAM.. no way to use the F-Droid client to browse the archives ?
Do try with patience…