Constracker

Import wallets
Import wallets from the Stargazer Wallet
Import tokens
Track your crypto portfolio

Inspiration

Constracker is inspired by the existing mobile crypto portfolio trackers with a desire to build an easy-to-use yet effective solution for the Constellation Network, where users would require minimum steps to get started. Constracker is a cross-platform app available on the Web, Android and iOS!

What it does

Constracker allows users to track their crypto portfolio on the Constellation Network: import wallet (manually or via Stargazer Wallet), switch between wallets, add tokens by the Metagraph ID, follow & unfollow tokens, see detailed stats and graph with the change of the Portfolio value and current tokens' prices.

There is no need to manually adjust amount of tokens in your portfolio. Constracker automatically fetches your current portfolio for the imported tokens and calculates everything on a go!

How we built it

Constracker is built using Flutter (cross-platform SDK) that communicates with Constellation Network Block Explorer API (current balance, token Metagraph ID validation) & Coingecko Price API (current price, price history) and Public JSON with tokens' data. There are some adjustments for each platform (web, iOS, Android) but the application is built on the top of the same .dart code.

Challenges we ran into

The biggest challenge was to build a reliable User Experience - both from User Interface and Backend perspective. Application makes several API requests on load, saves data to the application's local cache, and in case of hitting the rate limit - shows recent data.

It was also important to make sure that Metagraph IDs of existing tokens are properly matched with Coingecko IDs. For that reason, regularly updated public JSON was created that includes data for the Constellation Network tokens (e.g. El Paca, DOR) with icon, coingecko_id, decimals, symbol and name. This JSON serves as the source of truth and allows to validate, properly import tokens and fetch their prices. If token is not found in JSON, Constracker imports a token based on the user provided data and tracks amount of tokens only (e.g. El Paca is not on Coingecko). Every community member is welcome to submit PR request and add new tokens!

Accomplishments that we're proud of

I am proud of the User Experience of the app and how easy it is to start using the app. How lightweight yet effective it is - you can install it on Android, open in on the Web, get it on iOS. I also really like the line chart of the portfolio change, which you can track with finger/mouse and see the historical balance.

What we learned

Even though the application is built on top of Flutter and REST APIs, I learned a ton about Metagraphs and Constellation Network during the development process. Also REST API structure itself gave a good understanding on how things are structured and work on the Constellation Network!

What's next for Constracker

Publish Constracker on Appstore, Android market
Include more Price sources (not only Coingecko)
Better balance history tracking: at the moment app takes current holdings and extrapolates it backwards based on the tokens' price history. It should also include received and sent token transactions so that it also fetches historical amount of tokens * historical price.
More features: delete tokens (not just unfollow), different wallets have different watch lists..