Android application for managing cryptocurrency portfolio.
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Important
DISCLAIMER I started this project to play around with Android architecture components for my own knowledge. I do not pretend the code is a reference. Some functionalities and checks might be missing or incomplete. This project is not intended to be used in a production environment.
The purpose of this application is to allow easy retrieval of trading data from online cryptocurrency exchanges. It only allows visualization of data, it can NOT be used as a trading platform.
It has been kept very simple, by gathering only trading data needed to calculate your portfolio value and some statistics.
It is directly connected to major exchanges so you don't have to manually fill the orders.
Here is the currently supported exchanges :
- Kraken : https://www.kraken.com/
- Poloniex : https://poloniex.com/
- Bitfinex : https://www.bitfinex.com/
- Bittrex : https://bittrex.com/
- Create API keys in your favorite exchange platform (read only recommended)
- In the application, go to the settings page, then in the Exchanges menu, edit the concerned exchange to add the related keys (public and private)
- Still in the settings page, click the 'synchronize' button under the Synchronize with exchanges menu
- Enjoy a beer watching your million dollars
- Minimum SDK : 19 (Android Kitkat)
- Targeted SDK : 27 (Android Oreo)
Main theme is based directly on the raw
Material Theme for Android 5.0
(API 21) and above, else a Theme.AppCompat theme is used.
Thereby the Support libraries have been used for backward compatibility (v7). It adds support for the Action Bar user interface design pattern and includes support for material design user interface implementations (RecyclerView, CardView, etc.). The following ones have been used :
- Design Support library
- AppCompat library
- CardView library
- RecyclerView library
- ConstraintLayout library
- Java 8
- SQLite as basic embedded database
- Android architecture components
- Retrofit 2 as HTTP client helper (with GSON2). A logging interceptor has also been used for logging with OkHttp 3 (Retrofit 2 completely relies on OkHttp for any network operation).
- MPAndroidChart library for charts
Application has been implemented using the MVVM (Model-View-ViewModel) pattern as described below :
flowchart TB
style VIEW fill: #205566
style VIEWMODEL fill: #205566
style ADAPTER_VIEWHOLDER fill: #205566
style ROOM fill: #205566
style MODEL fill: #205566
style SERVICE fill: #205566
style REPOSITORY fill: #3d681b
style API fill: #806030
style DATABASE fill: #804030
subgraph VIEW
ACTIVITY_FRAGMENT(Activity / Fragment)
end
subgraph VIEWMODEL
LIVEDATA_OBSERVER(LiveData / Observer)
end
ADAPTER_VIEWHOLDER[Adapter / ViewHolder]
REPOSITORY[Repository]
subgraph ROOM
DAO(DAO)
ENTITY(Entity)
end
DATABASE[(SQLite)]
MODEL[Model]
subgraph SERVICE
RETROFIT(Retrofit)
end
API{{Exchanges API}}
VIEWMODEL --> ADAPTER_VIEWHOLDER
VIEW --> VIEWMODEL
VIEWMODEL --> REPOSITORY
VIEWMODEL -.-> MODEL
REPOSITORY ---> ROOM
REPOSITORY --> MODEL
ROOM --> DATABASE
MODEL --> SERVICE
SERVICE --> API
Application code has been organized with the following package structure :
- activities : UI interaction classes
- adapters : underlying views datasets management classes
- components : custom components / decorators
- dao : database access object interfaces
- entities : database entity classes
- helpers : helper classes
- managers : manager classes that acts as proxy between viewmodels and daos/services
- models : simple model classes (mainly used for services)
- services : services classes responsible for calling web services
- viewholders : view holder classes that holds view elements to speed up rendering
- viewmodels : viewmodel classes that store and manage UI-related data
Data got from online exchanges are stored in the local SQLite database :
- all assets from different exchanges are merged into a single
CURRENCYtable - all trades from different exchanges are merged into a
TRANSACTIONStable
Note: same currencies with different names are merged (ie. Kraken XBT becomes BTC).
That way we have a simple EXCHANGE - CURRENCY - TRANSACTIONS relation, and have no need to
call exchange API each time. Simply resynchronize the exchanges on which you performed new
operations (from the settings menu) to get up-to-date data.
This privacy policy sets out how we use and protect any information that you give when you use this application.
Should we ask you to provide certain information by which you can be identified when using this application, then you can be assured that it will only be used in accordance with this privacy statement.
We may change this policy from time to time by updating this page. You should check this page from time to time to ensure that you are happy with any changes.
When using this application, you may only be asked to enter your exchange public and private API keys so we can retrieve your public and private exchange data. We will NEVER ask you to provide any credit card number, wallet private key or other sensitive data.
The application may communicate with mentioned exchanges and with the CryptoCompare API to get live trading data.
Thereby we may collect the following information:
- any data available from the API related to the exchange(s) you have linked
- any data you may manually enter in the app
We simply use that information to display your trading data and some statistics.
We will not sell, distribute or lease any of your personal information to third parties. We will never transmit any data about a user without obtaining its prior permission and providing information about how and where the data will be used.
We will never display any advertising and/or send you promotional information about third parties.
Raw data is only stored in the local embedded SQLite database. Once in the app, it will never be sent over the network to any centralized server. Keys are AES encrypted before storage.
Android Auto backup is disabled, so application data will not be sent to your Google Drive account. If you need to backup your data, please use the backup/restore functionality from the Settings menu.
The backup/restore functionality writes CSV files to the internal storage in the application-specific directory so it does not require any additional permission. Your keys will remain AES encrypted in the backed up file.
I have planned to use Android Keystore System in the near future to store the exchange API keys but for the moment I simply used an AES encryption.
Therefore, we cannot guarantee the security of your data as any APK file can be easily decompiled. It's up to you to keep your application and related data in safe hands.
You can decide at any time to remove this application and your data will be gone with.
General Public License (GPL) v3
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.
- Bittrex API is broken and does not allow to retrieve order history
- Bitfinex API order history is limited to last 3 days and 1 request per minute -> use "Past Trades" endpoint that must be called for each pair...
- Backup / restore functionality simply backup and restore the exchanges list
- Paging need to be refactored because of deprecated methods