So it looks like the Kindle Fire supports sideloading, which is great, and supports it even without the use of ADB - a user can download an APK and tap on the "download complete" notification just as on any normal Android device.
However, when I actually try loading my app this way it looks really crappy in the Kindle's app launcher screen - it's kind of low-resolution in the "Apps" screen and it's extremely low-resolution as a recently-opened item on the home screen. It appears to be using the MDPI version of the icon in both places even though HDPI and XHDPI versions of it are available, but even one of those would look fuzzy next to the icons for the built-in gallery app / book covers / etc.
So: does anybody know where in my app (an extra manifest line, maybe?) I can embed a high-resolution app icon / book cover / etc so that the Kindle will use that instead of a crappily-upscaled MDPI icon?
Note: the following info is now outdated.
Apparently they're doing something funky. From the docs:
How do I get a high-resolution icon for my app to display on Kindle
Fire?
The icons on Kindle Fire are dynamically pulled from the Amazon
Appstore for Android. Side-loaded apps cannot use this feature. Once
you've submitted your app and it's live in the Amazon Appstore, your
app's appropriate icon will automatically be displayed.
Just to make you aware and remind :
The Carousel icon on the kindle fire should be as referred to the Amazon Guide Lines :
Kindle Fire (1st Gen) : 322x322 px
Kindle Fire : 365x365
Kindle Fire HD 7" : 425x425
Kindle Fire HD 8.9 : 675x675
But as per android standards , Launcher Icon Size is non rather than :
ldpi (120 dpi) (Low density screen) 36 x 36 px
mdpi (160dpi)(Medium density screen) 48 x 48 px
hdpi (240 dpi)(Highdensity screen) 72 x 72 px
xhdpi (320 dpi) (Extra-high density screen) 96 x 96 px
Working fine for me but had to change the version number of the app. so that the Kindle Fire would start using the new icons otherwise it kept using the old ones.
To cover as many Android devices as possible I used the following icon sizes: I believe the Fire uses 512 and 114
16X16
32x32
36x36
48x48
72x72
114x114
128x128
512x512