The problem Count_on_Me solves

The P2P App will be a tool to solve 4 existing Problems: Coordination, Speed, Compatibility, and Zero-Incentives - Count on Me is designed specifically for patients and donors to connect by blood type using geolocation. By being built with flutter, it will work for both Android and iOS platforms, with the trendy feature of being able to connect using web3.

A Coordination Problem
When a patient is in critical need of a platelet bag, doctors need to find a compatible donor. For that, they need to check the hospital inventory, which is usually low. The process is done by phone calling other hospitals and manually checking the nearby suppliers. Family members need to go on social media to claim for help of friends that are compatible. -
A Speed Problem
Every 15 seconds someone needs platelets. Platelets must be used within five days and new donors are needed every day. It is literally a run against time! The process of finding a compatible platelet bag as quick as possible can become a death sentence for those in need.
A Compatibility Problem
Willingness to donate does not necessarily translate into ability to donate. And that’s a problem. Many factors matter to donate. From having the right blood type, weight, age range, be medication-free, have no recent tattoos, not be sleep deprived. The list is huge and compatible donors are almost as common as unicorns. But even unicorns need to have thick veins to be able to collect platelets for about 2 hours.
A “Zero Incentives” Problem
Platelets donors are usually treated with the most attention, care and urgency as possible. Nurses almost extend a red carpet once a platelet donor is around. But NO FINANCIAL INCENTIVES are in the system. Donors pay for their transportation costs, and spend on average 3 hours in total (considering commute and waiting room time).

Challenges I ran into

Flutter is great for Android and iOS but there is not much documentation or online tutorials about its only web3 library. Today web3.dart (https://pub.dev/packages/web3dart) is the only tool I have to connect with the Ethereum ecosystem and NO-OTHER-BUIDLer is using this library. As a non-experienced developer, it was pretty hard to use the dart:js conversion library.

Not using JavaScript and React was a huge limiting factor to apply for bounties and integrating technologies with projects that I was interested in, such as Metamask, 3Box, Pepo/OST, Fortmatic.

I have a Solidity contract of donors/patients, with events, etc, but I don't know how to integrate the ABI.json of the contract deployed with my Application.

Front end was compromised to deliver a "console-log" proof of technical implementation. It looks really bad, but a team of one, is a big challenge to run against time in a hackathon of this magnitude.

I was helping to BUIDL a DAO called MetaGammaDelta during hackathon hours. Recruiting friends and being social is time consuming in a hackathon

I had no financial support from Consensys Grants or Eth Denver to be able to afford the costs of being here. I'm not currently employed and affording a trip abroad is very costly in my local undervalued currency (BRL)

Lack of documentation in dart or web3 flutter tutorials, 99.9999% of the developers are "flutter averse" or "dart averse" and can't help much.
+++++ Thanks for the invaluable help of Ivan from Prysmatic Labs for being brave to learn flutter on-the-go, tks for the support of Pepo team, Infura and Metamask to still incentivize me for submitting "something" when I was almost giving up as a hacker. And thanks to 3Box team for sending me a flutter example using web3, that unfortunately didn’t build using the dependencies provided due to software upgrades, and thanks to Abhimanyu121, and https://github.com/simolus3 for sustaining Open Source Flutter/Web3 projects.