Licensing model is not clear to me

Hi,

The license agreement states that 'PDF rendering engine for mobile OS (Android, iOS). One license will be valid per application on a single operating system. The above prices are per each license.'
This is not fully clear to me.
- Is the license valid for one OS or one OS version? For example, do I have to buy several licenses if I want to support serveral versions of Android?
- Do I have to buy a license every time I release a version of my app?

Thanks

1st point: 1 license are support for all Android Version from 2.2 to 4.4 currently.
and you need buy 2 license to develop both on android and ios.
2nd point: no need, if you has not changed you package name for APP.

Thanks for your explanations.
One question remains: what happens if a new version of Android is released after my app has been published (for example Android 4.5)? Do I have to buy a new license, or can I go on with the one I already have?

we will consider this, if a new Android version published.
and shall upgrade our library.
Generally speaking, it is free for you to upgrade.