Thanks for your replies.

Andy: Yes the Xpub format works great with the Xpub reader, but what about marketing?
Will I be able to sell Xpub files on Amazon and Google?

Lisa: Thanks for recommending Infinity reader and it was better than a lot of the others (the menus didn't keep popping up) .
What I found was that it didn't render my SVG files at all - just an empty box.
I know I can switch to Jpgs but SVG is very handy for my cartoons if I want to zoom right in and not loose any definition.

This article was very interesting regarding Epub readers on Android:

https://www.boblevine.us/the-fixed-layout-epub-missing-piece-reliable-readers-for-windows-and-android/

I'm still searching for the perfect Epub reader.

Did anyone get the features showcase Epub to run on an Android tablet reader?

I have tried Adobe digital editions, Gitden reader and Kobo ebooks readers.
There's no interaction and no sounds. Every time I tap the screen the menus pop up but that's about it.

The only thing that worked was the X pub on the Pubreader.

Everything works OK on a desktop PC with Adobe digital editions and with Readium for Chrome.

I'd just like to echo what others have said about the colouring book object.
It really does need the save feature. It would be upsetting for kids not to be able to save what they have done.

I'm working on a series of five printed books that will have a colouring book companion for each.

I'll be using Pubcoder to create an enhanced Epub for each book and would love to be able to incorporate the colouring book object into it, but really does need a save function.

Thanks for your response Andy.
I'm planning on learning Java Script so your link was very useful.
I haven't done any coding for years so it will be interesting to see how I get on.

I'm still evaluating Pubcoder and find it quite promising but a little quirky.

All the best
Phil

Does Pubcoder support two-finger swipe, press and hold, double tap, triple tap?

I'm just trying to build a KF8 mobi file with embedded audio but get the message
"Audio Object is not supported on KF8".