iTransit - Build an Android application from A to Z

By xngo on February 27, 2019


Below is more or less the log entries of my journey in building my Android application, iTransit. I build it from scratch and put it on Google Play Store. It took me 1 month.

It is an offiline application that displays bus and metro time in Montreal city.

iTransit - Main screen iTransit - Bus number screen iTransit - Stops number screen iTransit - Schedule screen

What I learned while developing the app, I wrote them as tutorials below. They might be helpful for other people to know what are the skills needed to build an Android application.

Developing app for mobile device has a lot of constraints. First, the screen is small. So you can not pack gazillion of fields. Thus, avoiding convoluted functionalities. Second, your app should not be big in size. Otherwise, it takes a lot more time for the users to download your app. I have to reduce my database from ~240MB to ~30 MB. Third, CPU power is limited. It forces you to rethink about your processes and questionning the need of each of them. Hence, it forces you to make simple processes. Lastly, everything is broken down into smaller chuncks. Therefore, coding is less complex and enjoyable. KISS principle at its finest here!

This tutorial is a work in progress

As I have time, I will write tutorial and link it here

Android Studio

  • Install Android Studio
  • Don't use Virtual Device, it is slow. 32bit on 64bit machine.
  • Where are the project files structure.
  • Debugging/Logging


  • Concept
  • LinearLayout
  • ListView

Navigation between screens

  • Passing data between 1 screen to another
  • Navigation bar

Data Storage

Performance with Layout

Shrink database

Put ad in your application

  • Add AdMob


  • Add logo

Upload to Google Play Store

  • Build APK
  • You have to pay $25 USD to Google to be listed on Play Store.


Upgrade database


Tests before release to production

About the author

Xuan Ngo is the founder of He currently lives in Montreal, Canada. He loves to write about programming and open source subjects.