Are you sure you downloaded the apk file and said that you trusted the file?
Yes
What error does it give exactly? Was there a previous version installed?
Yes, the previous version.
And another question, how the objects work is that I am a native Spanish speaker and I do not understand how they work from the descriptions.
(NOTE: it's android version)
Drag them to the little squares on the right side of the screen. The brown ones are your pockets, the grey ones mean they are equipped :)If you had a previous version installed, I recommend deleting it then reinstalling the new one.