Yes, all single Apps are available in the corresponding store of your device (MAC Store, Google Play, Windows store). You can find the direct links on the bottom of the shop page.

You actually don't need to sign up with PayPal, they allow guest payments and accept all major credit cards.

The questions and training methods of the App will help you pass on your first try. Focus on the group with the difficult questions and practice for a couple of days - that's all you need. I would recommend to read the blog posts I have written below to get an overview. 

Maintaining, uploading and programming for 4 different system takes a lot of time and effort so to cover my costs I charge for every device separately. I recommend you get a device bundle.

This package gives you all you need for your start in China. It includes a ebook (A course with all the HSK1 vocabulary and audio), full access to my training App including audio spoken by a native Chinese woman and real exam simulation. All the material was created with a native Chinese professional.

I do this already for a long time and helped and helped thousands of students to get their driver's license. Nothing beats experience and the help of the community.

I sold PDF versions of the Chinese driver's license a couple of years ago but people started to resell and share this without my permission so I stopped doing that.

Of course, all the Apps from the stores can be downloaded for free and have a trial version. When you want to take a look at the questions you can try them directly here on the website.