We are not familiar with development for Android and hence we can't give you an answer whether it will work or not.
The API client library is only two simple .java files with dependencies on java.util, java.io, java.net, and javax.net.ssl. You can take a look at Client.java here:
https://pdfcrowd.com/static/clients/java/Client.java.html. The other .java file (PdfcrowdError.java) is without any external dependencies.
It would be great if you could try it out and report back if it worked. Thanks.