Hi all,
The GeoQuiz APP runs perfectly on AVD manager. However, It could not be installed properly on the cellphone which is connected to my computer. Here is the hint:

How could I fix this problem?
I am looking forward to your reply.
Best wishes,


Hi all,
I have solved this problem this way:
(1) generate .apk file;
(2) move it into the smart phone;
(3) install;
I guess the problem is due to missing of JKS.
I am interested in other ways to fix it. If anyone has, do not hesitate to tell us.
And I suggest the author should refer this problem and its solution in Chapter 2 of the next edition in case of puzzling the readers. Anyway, I’ve spent more than three hours to handle it.

Best wishes,