Second I want to say that while my android app may not be all that useful,
it probably is the first app in Google Play to use the patentsview web service! And hey, it's free without ads or in app purchases and is using four of the seven patentsview endpoints.
I used mit's App Inventor to write my app as explained here. I am a java developer but I haven't yet learned the sdk so I only know a portion of what's needed to write an Android app in java. But then I came across a book¹ on App Inventor at my library. Essentially I found a short cut to getting an app in Google Play! (I put it in as a beta version since it's not fully polished or overly useful.)
¹ App Inventor 2: create your own Android apps / David Wolber, Hal Abelson, Ellen Spertus, and Liz Looney. Second edition ISBN 9781491906842 (paperback) 1491906847 (paperback)