This app fetches routes and does optimizations by using Here Maps API and allows downloading them as .gpx files and as a link to popular navigation app Mapy.cz.

The app was fully built by using Firebase services:

• Authentication allows only invited users to log in.
• Firestore stores data about added routes and results generated by the app backend
• Cloud Functions run custom logic to generate the routes files and optimize them
• Storage bucket stores files for download for a limited time

Using Firebase allowed me to deliver the MVP very quickly by not worrying about setting time consuming things like authentication. The generous free tier on Firebase also makes the app free to run for the limited amount of users using it.