Gadgets, for example, flash drives, designed for cold storage of keys. It is inconvenient to trade and make transactions with their help, so they are practically not in demand among ordinary users.
KeepKey hardware solutions are like mp3 players
But they are very popular among investors who prefer long-term investments
. This is due to the fact that such gadgets can not be hacked "from the outside"
because they are not connected to the Internet and have built-in protection against unauthorized access. What they have the best safety record.
. Available in 2015, supports Bitcoin, Ethereum, Dogecoin and Litecoin. Cost - around 100 dollars.
● Ledger Nano S
. Available since 2016, it supports 40 major coins. Cost - up to 100 dollars.
. The first hardware wallet, produced from 2013, supports about 500 coins. Cost – 100 dollars.
They represent a paper with printed out a public address and a private key. Information can be presented “as is”, in the form of QR codes or encrypted. A great option for long-term storage of virtual money for those who do not trust digital devices.
Paper cryptocurrency wallet created with bitaddress.org
Paper wallets should be stored in a place where they will be hidden from prying eyes, video cameras, and at the same time they will not be threatened by fire, soaking, moisture and insects. The loss of a paper key or its destruction
is the loss of money without the possibility of their return
● Bitaddress.org. The most popular Internet service for creating paper keys with encryption of information through QR codes.
● WalletGenerator.net. Convenient service that unloads the distribution kit to create a paper wallet on the user's device so that no one on the network has the opportunity to “peep” something.
● MyEtherWallet.com. Service creation of paper wallets for etherium. Not very convenient, but users love it.
7 stages of the development of cryptocurrency wallets
When a customer addresses to the developers of cryptocurrency wallets (or his staff members), he should have a clear technical task (TT) with a detailed description of his vision of the product and the functions that it should have.
1. Login form.
2. Personal profile.
3. Conversion Rate.
4. QR code scanner.
5. Trading services.
6. Push notifications.
7. Password and PIN protection.
If the TT is not written, the developers ask the client (chief) to fill out the brief - a list of questions, the answers to which will help to prioritize the project, its objectives and goals. In addition, using the brief, you can choose the optimal development model: agile - development goes through iterations (step by step), waterfall - the application is developed entirely.
At the end after filling the brief we get:
● development methodology;
● description of goals, objectives and basic functionality of the wallet;
● target platform: macOS, Android, Windows, UNIX or cross platform.
1: Evaluation and planning
At the beginning of any development, the question is always asked: “What is the cost?”. And almost immediately after it comes the following: "How long will the development take?" To get answers to these questions, you need to evaluate the project and draw up a rough work plan. It usually connects the project manager, which can be both on the part of customers and performers. His duties are to coordinate the work of the team and communicate with the customer.
When evaluating a project, the TT, brief and customer’s wishes are coming under review. The time required to develop an application and test it is evaluated. Pain points in the technical task and previously unused product usage scenarios is revealed.
Express evaluation is done during the day. It gives a rough idea of the number of necessary labor hours that are needed to create the finished product. Detailed assessment is carried out within two to seven days. Thanks to it, you can get an accurate idea of when the customer will receive a wallet ready for use and what it will be like in the end.
At the end we get:
● scope of the project;
● development budget.
2: Business analytics
During this phase of development, key requirements for the final product are determined, schemes for the interaction of a regular user with an interface are built, options are proposed to achieve what is intended, and a basic scheme of user interest is created.
Business-analytics is not always conducted by the developer. It happens that customers fulfill it on their own or come with a list of ready-made requirements. In this case, the customer (or the one who conducted it) is responsible for the quality of analytics.
At the end of business-analytics we get:
● specification of functional and non-functional
● basis and user interface specification;
● detailed development budget;
● worked out development plan.
3: Application design
If the customer does not have a ready-made user interface design (UI / UX), the development team creates it from scratch. First, the UI / UX base and wireframes are created, which are transferred to the customer, after its approval, a visual design is created taking into account all user scenarios: a prototype, graphics elements, a map and a screen switching scheme, etc.
Prototypes can be static or interactive, depending on the wishes of the customer. With it, you can visually see how the interface will look through the eyes of the user. During this process, the product acquires the final look
, so it is important to establish feedback with analysts and marketers, which will tell you which design option
the final users will like and will respond to all customer requests.
At the end we get:
● preliminary interface design;
● map and screen switching scheme;
● UX/UI specification.
4: Coding start
After the technical task has been drawn up, the project has been evaluated and the design with the prototype has been drawn up, the programmers start writing the code. Written in TT and plans is implemented in a binary code, the application logic is connected with the server part and the blockchains of cryptocurrencies. Design sketches are also embodied in the code - UI elements and interface styles are written.
To speed up and reduce the cost of development, open-source libraries can be used: Chain-java, Bitcoinj, Blockchain, Coinbase and others. These are sets of ready-made software solutions that can be used like elements of the Lego constructor.
The designer connects after the design is composed. He checks how well the programmers implemented the styles: whether the colors are right, how well the styles correspond to the designer’s idea, how rounded the corners are, whether the design is adapted for devices with different sides ratios.
At the end of this stage we get:
● ready for testing version of the product (MVP, alpha version);
● design corrections.
5: Testing and bugfixing
When the code implements a part of the wallet's functionality, it starts testing. Experts check the application with all possible scenarios for its use in order to identify flaws, errors and bugs. All of them are entered into a special “bug list” that is sent to developers for corrections.
This is how product testing looks like
There may be several stages of testing:
1. MVP testing.
2. Alpha-version testing.
3. Beta-version testing.
4. re-release (acceptance) testing.
At the last stages, not only the application code and compliance with the intended design, but also usability is checked - how convenient is the wallet to use, is the interface clear at the intuitive level.
At the end we get:
● minimum number of bugs or their absence;
● simple, intuitive interface;
● pre-release product.
After completion of testing and improvements, analysts, testers, designers, marketers, developers and the customer should give the go-ahead to complete the project and its release. If everything is fine, it will be added to GeekHub and Google Play and the App Store digital marketplace.
Both the developer and the customer can add the wallet to the marketplace listings. To do this, you need to contact the employees of digital services and pass their check for compliance with their requirements and legislation.
At the end we get:
● ready cryptocurrency wallet placed in GeekHub and marketplaces.
7: Technical support and development
The history of the development of a cryptocurrency wallet does not end with the release. If the customer and / or users found bugs, they should be eliminated. In addition, the first few months show that you still need to “finish” or redo it so that the wallet becomes more convenient and functional.
If the development of the application is provided in the initial plans, then the development team simply continues to work on the project. If this is not provided for, a maintenance contract is drawn up or a new development stage starts, taking into account the obtained data.
At the end we get:
● maintenance contract, which may include 1 year of project development (making relatively minor improvements) and a guarantee for eliminating bugs.
The cost of developing cryptocurrency wallets