As another option, this is a good free alternative you could try:

https://www.affinity.studio/download

I bought it (before it became free) and once I got used to it found it really good.

Android?

Well, in a way that’s true. You don’t need any specific tech or device to read it, just your eyes.

If someone dug this thing up in a billion years, will they have the device to read it?

What is the best source for audiobooks?

I guess we’re not ready for that yet, but our kids are going to love it.