Simple, small, experimental free app to boost your speaker/headphone volume, optimized for the Kindle Fire.
USE AT YOUR OWN RISK. Setting the volume too high really can destroy speakers or earphones, or damage hearing. IF YOU HEAR DISTORTED AUDIO, LOWER THE VOLUME (but it may be too late).
Due to an Android issue, this app will not on most Android 4.2.x and 4.3.x devices. It should work on earlier and later ones.
By installing this application you agree that you will not hold its developer responsible for any damage to hardware or hearing, and you are using it AT YOUR OWN RISK. Consider this to be EXPERIMENTAL software.
On the Kindle Fire, you can make Speaker Boost show up on top of an app by tapping the left side of the status bar, and choosing "Speaker Boost".
It did what I needed - and I'm only on 10%. The volume was so low on my Fire7 (2017) I could barely hear anything at 50% on the volume scale. Now with the boast set at 10%, I'm plenty loud at about 40% on volume scale.
It worked, but I wish it was louder. The main problem is the speakers on my kindle should be better. It states on the app not to raise it over 40 % or it might damage the speakers. I set mine at the loudest 60%.
Using it on my android, I had to restart the phone every time I would play another song. It is a great app when it works, but those constant restarts are a real pain. I start the app and it amplifies the signal just fine, but then when the next song comes on, the signal drops back down even though the app is still active. I stop and restart the app, but no good. I have to restart the phone to make it work again.
Little bit hard to rate as it did make the volume louder BUT the speakers on my Fire HD 8 tablet (7th gen) have a very grainy sound. Not really a fan of amplifying poor quality speakers so only used it for about 2 minutes. Was very conservative with settings as didn't want to damage anything so had Fire HD on 88% and speaker boost only on 21%. If your tablet speakers are decent then this app is probably ok.