Some time ago I wrote a simple Android app to search for images using Google Search API, I thought it is worth sharing in case someone else needs to do the same. I had to create a custom search engine (https://www.google.com/cse/) and create an API project (https://code.google.com/apis/console) to get set up. The rest is ordinary stuff you all know.
There is one thing to mention though: Using Java search API you have to specify the web sites you want to search in. You can’t search the whole Internet using this API. You could do this using image search API, but since it is deprecated it is not worth investing in.
The complete working code along with a pre-built .apk is also provided. I have implemented other interesting features too like search suggestions and infinite loading, which will become handy down for you the road.
Simply clone https://github.com/normanatashbar/imagesearch.git or download by clicking here. Please remember to change the search engine ID and API key with your own if you are using this code as a base.