How many words are "ranked"? Are English words also ranked?
Spanish words are ranked from 1 to 50,000. The English frequency list/database only goes up to 30,000.

How much does it cost?
The app is free. Please give me five (5) stars on the app store!!!!

What technologies did you use to build the app?
I built it with React Native, and on the "server-side" I used Google Cloud and Firebase cloud functions.

Can you build me an app like this? Or some other kind of mobile phone app?
Yes, I can build virtually any kind of app you could possibly think of. The main question is whether or not I have a full-time job at the time you make your enquiry. My contact information is listed on the "About" page of this site here.

Where can I learn about web development?
You could start with my web development blog.