As part of my embracing of cross-platform, I’ve taken some time this weekend to port my iOS transit app, GWTA, from native iOS (Swift) to Flutter. My goal is to get a sense of the differences in the approaches using the simplest app I have.
I’ve included some breakdowns of the things that I did along with the approximate time it took to complete.
Project Management Tools (25 minutes)

- Screenshots (what you’re building) – these were taken from the iOS Apps
- Trello Board – I duplicated the stories (cards) in the iOS version and moved them into a separate list
Environment Setup (155 minutes)
- Install Flutter
- Install iOS Simulator
- Install Android Simulator
- Install Visual Studio
- Install Android Studio
- flutter doctor – check that everything is installed correctly
- Issues:
- had trouble locating the Flutter SDK but Android Studio downloaded and installed without issue, allowing it to be seen by Visual Studio
- Having a later version of Cocoapods displays a warning in
flutter doctor
- for new project, I had to run
sudo gem install cocoapods
I wonder if I have to do this for every project multiDexEnabled true
in app/build.gradle- DON’T manually edit the Podfile. Flutter will handle it.
- Issues:
Where Do I Start?
After setting up the development environment, where should I start with the development process? I have a clear idea of the screens that I need as well as the data I want to display. I decided to take a top down approach and start with the bus routes themselves. I’m going to scaffold out the main screens of the app and fill in the UI as I go.
Screens
- Route List
- Route Stop Detail
- Route Schedule
- GWTA Information
The first fork in the road was after finishing the basic tooling and app setup, I could display sample data but I wouldn’t get much further without the actual bus route stop information. I had a choice of building out the UI with small sample data sets or setting up the actual route data on the backend. Gravitation towards my backend dev tendencies and to ease my earlier tooling frustrations, I opted for the latter. I knew I would have to eat the Cloud Firestore frog eventually and was hoarse from yelling at VS Code/ Android Studio and I wanted to move forward.
Backend (210 Minutes)
The iOS version has a static list of data. I’d like to move that route data into Firebase to make it accessible to both platforms and update when necessary. In reality, the route information doesn’t change very often but having it located here will prevent me from having to release a new version of the app when/if it does.
Setup/Install Cloud FireStore (25 Minutes)
I’m tempted to start with the Firebase (Cloud FireStore) implementation and have the app download the route and stop information but I’ve had so many bad hackathon experiences starting with the data that I’m a little gun shy.
Create FireStore Models (75 minutes)
One of the challenges I had in the previous version was that some stops are on multiple routes (e.g. The Transfer Center) so I duplicated the stop data for each route. It would be nice if I could represent that a stop was in on multiple routes using the colors, similar to what I’ve seen on transit systems around the world.
- Create Routes in Firestore
- Create Route Stops in Firestore
ETL Process for Stops ( 145 minutes)
Extracting stop data from native iOS app => spreadsheet and converting to JSON to import into Cloud Firestore
Results

Ironically, I don’t have much front-end progress to show after 8 hours but the route data is loading from Cloud Firestore and I have successfully imported the stop data multiple times (testing the ETL process). I’ll chalk it up to beginner’s luck. I expect better from the next 8 hours with the focus on UI/UX. I’m certain there’ll be a few more headaches and roadblocks as I learn more.
Next 8 hours
Add Map UI
One of my bigger disappointments with the existing iOS app is that it doesn’t make great use of maps. I’d like to show users the closest stops to their current location along with the next arrival time.
Cloud Firestore Functions
The ETL process doesn’t create the needed geopoint type needed to represent each stop’s location on a map so I will add a trigger to create the field when a new document (stop) is created.
Add Schedule Info UI and Backend Data
The buses runs on different schedules on weekdays versus weekends and I want to display the next arrival time for each bus.
Add GWTA Information UI
These screens will probably remain simple webviews that link to the information on the GWTA website. I