I am developing a Human Activity Recognition android application. Currently, I am at the Design stage where I am designing the architecture of the app. I am using the MVP architecture pattern. I have to note that I am learning how to develop a software architecture while thinking about the design of my app so please take that into account.

Now, my question. In terms of visual structure and using the UML language to represent my design, can I improve something?

Component diagram (Astah)