After several days trying to sideload various apps from the Google store and other things trying to get a free aquarium I broke down and paid 99 cents ($1.08 I believe with tax for my locality) and ended up with:
Amazon.com Peaceful Aquarium HD Appstore for Android
It's actually far better than any others I've tried, on or off the Amazon App store.
Multiple aquariums... Fish movement doesn't repeat or if it does it's a lot more than 20 seconds that another Aquarium app wa giving me.
In my research I found some apps were merely showing youtube videos of fish.
Was disappointed.... fisk tank simulation looked so real on Windows even 15 years ago- I thought by now they'd have Android apps where you could pick what fish you wanted and drop them into virtual tanks- and each fish would get random movement- and not just one overall video being played time and again.
If anyone finds a better Aquarium App for the Amazon Fire TV please let me know.
Amazon.com Peaceful Aquarium HD Appstore for Android

It's actually far better than any others I've tried, on or off the Amazon App store.
Multiple aquariums... Fish movement doesn't repeat or if it does it's a lot more than 20 seconds that another Aquarium app wa giving me.
In my research I found some apps were merely showing youtube videos of fish.
Was disappointed.... fisk tank simulation looked so real on Windows even 15 years ago- I thought by now they'd have Android apps where you could pick what fish you wanted and drop them into virtual tanks- and each fish would get random movement- and not just one overall video being played time and again.
If anyone finds a better Aquarium App for the Amazon Fire TV please let me know.