An Android app gives a huge advantage. It shows that you can apply knowledge and it’s easy to verify. Usually both on screen and in the code if the source code exists in a public VCS repository (usually on Github).

Even without checking your repository, people assume that you can ship features, fix bugs, use GIT. So it’s an ultimate proof of skills for Junior Android Developer. Especially when the repository has many commits with informative commit names.

This is an example of good commit guidelines.