Works Perfect, thanks!!!

Hi,
My book was designed in PubCoder back in 2015-6. It was originally designed for tablets (iPads and such), hence, the base resolution was 1024x768 (aspect ratio 4:3). In renditions of 16:9, the top and bottom were cropped. I made sure nothing important is cropped, though.
These days I'm bringing it back to life. I want it to work on modern phones, but nowadays some phone's aspect ratio is 20:9, and now it crops too much.
I thought of adding a new rendition - 20:9, and change the backgrounds in this rendition to new, wider images in which I'll add some background on both sides, not a big deal (in most pages).
The problem is that when I use these backgrounds, none of the overlaying/animations fit. Everything becomes too big and out of place, because the size adaptation is done in the wrong direction, or something like that.
If I keep the app as is, I get white strips on both sides, in 20:9 phones.
My questions are:

1. Is there some trick to use wider images when the base is 1024x768, or do I have to start all over with wider backgrounds?
2. If I keep it as is, how can I set the side strips to black and not white?

Thanks for reading such a long post, and for your help!
Ranco

My app supports two languages - English and Hebrew, using different renditions.
In the Project settings, I selected XPub, and:
Page format: 16x9
Orientations: Landscape
Localization: English (with star) and Hebrew (both are selected)

I exported using: Android, All Pages, Wi-Fi.
The app runs
I have a button in the first page that triggers "Open Localizations Menu"
Still, when I export and open the app to my Android phone, the only option is English.
What am I missing?
Thanks!

Thanks, that did the trick!

Hi,
I'm trying to build an .apk file.
I selected to export Android --> All pages --> Wi-Fi. I have latest JDK and Java run-time freshly installed, but still, I keep getting this message:

Failed to build <app>
Error decoding apk
Input file (com.pubcoder.pubplayer.apk) was not found or was not readable

Any idea what I'm doing wrong?
thanks,
Ranco

I understand. Still, since I have a lot of interactions, KF8 is irrelevant. I'm not interested in the "regular" kindle devices, only in the Kindle Fire, which is practically an Android device. In that case - what should I upload?

Is it the same as google play store?
Which binary should I upload: "Ad Hoc Distribution" or "Google Play Store" distribution?
thanks,
Ranco

Sure, that's what I meant.
BTW, I found a way to do it in Java, but not Javascript:
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

Many games do keep the screen on at all times. see Candy Crash for example. Obviously, it consumes a lot of power, but at least for a self-reading book it makes sense (to me).

There's a nice shortcut, though. you don't need to drag new image objects to the stage and then place an image in it for each of your images. You can simply drag all your images from the assets tab into the stage (but not onto an existing object) and a new objects will automatically be created for each image. Then, it is just a matter of placing the objects in their location, and sorting the layers (drag/drop). Very easy. I built a 16 pages interactive children's book in 3 days, with dozens of elements (images, animations and audio).
Ranco

There must be an option (if there is, I can't find it...) to keep the screen on. A book is usually read aloud by a narrator, the kids listen and might not touch the screen for a while. Then, suddenly, the screen turns off, and when awaken (by one of the parents...), the page reloads and narrations starts over from the beginning. This is a big issue, in my eyes.
If there's a way around that, please advise.