Spellex corporation is one of the leading reading and writing application developers based in Tampa, US. During it’s more than 30 years of history, Spellex has created software that helps millions of people around the globe to write better texts and improve their literacy on the go.

Spellex had a challenge with finding software partner competent in Windows applications development to work on new functionality they were planned to introduce in the Write-AssistTM product.

After the initial discussion, Existek has been chosen as a provider of development services for Spellex Microsoft add-in project. The main evaluation criteria were the rich expertise in desktop software and experience in the development of the writing assistive software. We were a perfect match for this job.

In the following case study, we’ll explore the objectives Existek was tasked with and how we achieved the development goals with our execution.

Project Technology Stack

.NET, Windows Forms, WPF

Timeframe and Workload

2 Developers, 2 Months


Existek has received an assignment to implement some new functionality and improve existing features of Spellex Write-AssistTM. Spellex Write-AssistTM is software oriented on the improvement of Microsoft Word users’ experience. It functions as an add-in built in Word interface to provide a user with convenient access to new options in one place. It is designed to help people with learning disabilities as well. In order to do that, Write-AssistTM introduces Zoom View feature to make reading easier, advanced text-to-speech option, text expander, and what is most important – the spelling report function which makes the summary of misspelling in the text, shows the misspelled word, replacement suggestions and the sentence with that words. Spelling report designed especially to help people who make repetitive mistakes to see them in one place and thus improve their literacy.

Development of these features required some specific desktop software know-how. Implementation was related to some challenges with the system logic behind MS Word, such as keystrokes and even mouse commands like simple scroll were working on the general system level and couldn’t be interacted with within the Word code itself.

Here is the list of the features we had to develop for Spellex Write-AssistTM:

  • Zoom Ruler – we were asked to significantly enhance this feature with new options and controls. At the moment when we start to work on it, Zoom Ruler was simply launching Windows Magnifier Tool with the default options to select the zoom lens and zoom level while Spellex needed it to be way more flexible for the user.
  • Spell Check Report – report with the summary of all misspelled words in the document, possible correct forms of these words, list of the sentence with those mistakes to help users locate them easier, and the list of words that were misspelled and fixed on the go with the final variant of how a user corrected his mistake.
  • Audible Alerts – the features which providers user with sound notification after he/she made a spelling mistake. Audible alerts should be enriched with the interface where the user can disable/ enable it, choose the sound for the notification and set the rules when the alerts should be played.
  • Licensing System – Spellex asked Existek to develop and implement a new licensing system with the trial period, licensing logic, the utility for the license keys generation with functions to assign the attributes to the keys such as the start/ end dates, type of the licenses and components of the solution suite purchased by the user.


As a professional outsourcing company, we always split the collaboration into three main stages: requirements analysis, research, and finally the development and implementation. The same approach was applied for the Spellex project which led to the predictable outcome above the client’s expectations.

In addition, some of the features were improved and performed better than it was planned because our development team found unique solutions that allowed software to overperform. For example, Spell check report feature is now able to form the PDF with the report itself immediately after the user pressed the button. Previously, the delay was necessary due to the Word’s spell checking algorithms which require time to process text with a lot of variables and parameters.

Let’s categorize the work for each feature in development and see Existek team managed to implement needed solutions:

  • Zoom Ruler – this accessibility tool was made to be more convenient and give the user more control over the area that should be zoomed as well as over the Word’s controls, even when the lens is applied. Our main task was to make the Zoom Ruler not just something people with reading difficulties launch from time to time to zoom in some parts of the text here and there, but also make it a tool that can be constantly used for the document editing. In order to do that, we reworked Magnifier accessibility feature the way it can be used on the screen all time, helping the user and not causing any distraction. The active area is now formed in a rectangular shape according to the document width, acts like a ruler that zooms in three to five lines of text, and can be moved up and down the document. What is more important, the document now can be edited and scrolled just as usual even when Zoom Rule is applied, which was the main idea behind this feature.
  • Spell Check Report – when we started the work on this function, it was on the initial development stage and, basically, we had to rework it from scratch. Now the PDF report is forming with the use of XML based on the branded template provided by Spellex. Previously, this feature was unable to form the report properly. We have used the standard Word functionality of the spell checking and misspelled words replacements to provide users with comprehensive analytics of their texts.
  • Audible Alerts – as it was previously mentioned, work on this feature was related to some limitations of the Word and Windows code structure. Except for the selection of the text with the mouse, all other users actions including keystrokes and scroll were rendered in code on the system level and couldn’t be modified with regular Word developers tools.  Using Win 32 API our development team bound the commands to the Word window via C#. In addition, we have created the settings window for this feature to allow users to adjust it according to their notification preferences.
  • Licensing System – Spellex needed a new licensing system that would be both secure and simple for their trial and paying customers. We have implemented the solution that stores the data (package, expiration date etc. ) about the license locally on users machine in an encrypted file. Leveraging Windows forms for dialogue windows the notification about the trial activation, time left and expiration was introduced. Also, we have created the utility for Spellex staff that gives them an ability to generate the keys with all the information about the license like the type of purchased subscription, end date and more in a few simple steps.


The main goal for this project was to create some unique features often requested by their clients but missing in the stock text editor. This was meant to give our partners an advantage over the competitors. And so it happened. As a result of this engagement, we have delivered the solutions within time and budget, and according to the RFP and specification requirements provided by Spellex.

Spellex team sees its mission in helping people with reading and writing difficulties like dyslexia or an autism spectrum disorder relating to written communication. The software suite leverages the vast set of accessibility features in order to assist people with disabilities with their everyday life and work.

As the final result of our collaboration, now Spellex Write-AssistTM stands out among the most convenient tools for people who want to provide themselves with so much needed extra assistance while working in a familiar MS Word environment.

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