Assassins App

Abstract

Assassins Mobile App

Faculty Advisor: Dr. David Gallagher

Students: Henry Anderson, Dilean Muñoz, Hannah Oaisa, Corrissa Smith

Technical Architecture

The Assassins app is created using Flutter and Google’s Cloud Firestore

database. It consists of four main “layers”: the database (in Cloud

Firestore), the database API (implemented in the app using the FlutterFire

library), the app objects (an in-app abstraction of the data), and the UI.

These layers are kept as separate as possible to modularize the code.

Cloud Firestore

Cloud Firestore is a document-based database. Unlike a typical

relational database, which stores data in tables associated by various

unique-ids, data is stored in a hierarchical format of collections and

documents (loosely similar to the idea of folders and files). As a result, data

is stored in a very JSON-like format, mimicking how the app objects will

store data. Cloud Firestore is external to the app.

Database API

Within the app’s codebase are functions that control reading and writing

from the database. These functions ensure that data is updated in real time

by attaching listeners to Firestore documents. When a listener is triggered,

the database’s listener code passes the new data to app objects and pushes

a global “update” ping to the UI. With a relational database, some sort of

ORM (object-relational mapping) framework could have automated some

of this API, but because we used a document-based database, we

constructed these functions ourselves. The FlutterFire library provides

good support for reading, writing, and listening to Cloud Firestore.

App Objects

The app objects store all the relevant information about players and

games. They call database API functions as necessary to read and write

data from the database. However, because of the API’s abstraction, they

remain agnostic as to what the database really is and how these reads and

writes actually work.

The UI is built using Flutter’s stateful widgets. These widgets are given

the app objects (ie, games and players) they are supposed to show. The

widgets are subscribed to a global update stream that informs the widgets

if any app object’s data has changed. That way, the UI does not deal with

the details of an app’s data changing—it is simply instructed to refresh the

page.

Development and Deployment

Apple Instructions

Step 1. Install TestFlight

Step 2. Scan QR code

Step 3. Join the beta and install the

app!

Android Instructions

Step 1. Scan QR code

Step 2. Tap on the .apk file

Step 3. When prompted, go to

settings and enable the installation.

RE-ENABLE THIS SETTING LATER.

Step 4. Install app

Language

The Assassins app is built in the language Flutter, which is based on Dart. Flutter is a

cross-platform language, meaning the app does not have to be rewritten for Apple/iOS

and Android devices.

Development Environments

Flutter is a cross-platform language, but it still needs to be compiled for each

platform. As the Android platform allows developers much more ease of access (iOS

development requires a Mac computer and is much more difficult to test on a real

device), most of our development was done in Android Studio. One member of the

Assassins team regularly tested the developing app on iOS using Xcode. Most cross-

platform difficulties involve connecting the app to outside resources, such as the

database and notification streams. Otherwise, there have been very few cross-platform

problems.

Deployment

Deployment of the Assassins app is currently in its beta phase. Deploying a beta app

to Android devices is relatively simple: an .apk file can be distributed directly to beta

testers and installed by them. (Beta deployment can also be done through the Google

Play Store, after the app and developer are registered). Deploying a beta app on iOS is

much more difficult and requires an Apple developer license. To fund this license, an

alpha version of the app was taken to Cedarville University’s entrepreneurial contest,

The Pitch, where it won second place.

Anticipated Impact

We hope for the Assassins app to simplify the experience of playing assassins,

making the game more accessible and streamlined. Short-duration games may

become more common, as the app eliminates the work required to organize them. We

believe that technology and games should be used to connect people and support real-

life interactions, rather than replace them.

The Assassins mobile app is a tool created to facilitate the popular campus game of

Assassins, common to Cedarville University and other youth communities. In a game of

assassins, players are assigned targets in a single, randomly ordered loop, and

“assassinate” each other with a designated “weapon” (potentially a plastic spoon, nerf

gun, or water gun). Once a player assassinates his target, he is assigned his former

target’s target, and assassinations continue until only the winner remains. Assassins

games can vary widely in duration, ranging from half an hour to several weeks.

Traditional tools for managing game information and distributing target lists include

spreadsheets, emails, and group messaging. As a result, creating and distributing the

target list can be time-consuming, and short-duration assassins games are

comparatively more work to organize and are therefore less common. To address the

hassle in organizing games of assassins, the Assassins app keeps all game information

on one platform and allows users to create, join, play, and moderate games of assassins.

The app is designed using Flutter, a cross-platform language, to enable release to both

Apple and Android platforms. It is backed by a Google Firestore database, and the back-

end code is designed with modularity in mind to make it easier to maintain and update.

By streamlining and enhancing the management of Assassins games, this app will

simplify the game-playing experience and make Assassins more accessible

User Interface

Wireframe

Mockups/High-Fidelity Designs

AppUser

Game

Player Player

Player

A sample of the

database’s schema

An illustration

of the

app objects

and their

relationships

Download the Beta

Note: The app only supports sign-in with Google