Read through this thread to begin to understand what you need to do to create EPUB files from InDesign:
Creating an EPUB from InDesign has not so much to do with Apple or Android tablets, except that you can proof EPUBs in EPUB reading apps like iBooks on an iPad or other device.
He/She was actually asking for an ebook app, not only the ebook. From what I know and understand, he/she was probably referring to the DPS.
@aliceleung: You may start here: http://www.adobe.com/products/digital-publishing-suite-single/faq.html
Unfortunately, creating an app is not what Indesign can do. And the DPS is very expensive...
You just gave a link to DPS Single Edition and then went on to say it's very
expensive. It's free with Creative Cloud. ButSingle Edition is iPad only.
For Andoid you'll need pro or enterprise level accounts.
Lots of time those asking a question don't really know what they want. I'm cued in to answer questions about "making an eBook from InDesign" so that's the way I answered it.
There isn't such a thing as an "eBook app," there are tablet apps though that may be what he/she was asking for.