PDF Conversions – Today’s Necessity

Being a college student, I often find myself at the print shop, carrying with me all kinds of documents to be printed – fee slips, academic transcripts, scanned copies of handwritten notes etc. While apps like CamScanner help in creating PDF copies of class notes, their functionality is limited to images that are directly captured by the app(s). Furthermore, the only file formats recognized at the print shop are JPEG, DOC(X) and PDF.

That’s why I have been scouring Google’s Play Store – in the pursuit of an app that can convert all my files to PDF copies, and into other formats, as and when required. One such app that fits the bill is PDF Convertor, developed by Cometdocs.

Before reviewing the app, it is imperative to expound a little on the history and advantages of the file format this app is built around – the PDF.

The emergence of PDF

Short for Portable Document Format, it has a legacy spanning more than two decades, with its first version released on 15 June 1993 by Adobe as a proprietary file format. What made its popularity soar to new heights was the ISO 32000-1, a Public Patent License, which allowed anyone to make, use, sell and distribute PDF-compliant implementations, without paying any royalties to Adobe.

What makes PDF so special today?

There are practical reasons for PDF being the de facto standard for electronic file types. Its capability to convert itself to print-ready graphics on paper, while preserving hyperlinks, images and text embedded within it makes it a versatile format. The cherry on top is its file size, which is much smaller than its JPEG counterpart, thanks to the data compression algorithms it uses.

Another factor is its OS independence, which allows it to look the same across all operating systems, making it more portable. Further, with recent versions of Android supporting PDF, its user base has expanded even more.

Having explained the PDF a little, it’s time to focus on the app itself.

The app’s interface (UI)

On opening PDF Convertor for the first time, the user is greeted with a blank screen, to which files can be added for conversion. There are a total of 24 conversion types to choose from, with 7 of them available as paid features. As of 25th November 2017, the full pack is worth 790 INR, while a la carte conversions are 250 INR each. I was especially interested in its capability to convert XPS to PDF, a hitherto locked feature for me. (XPS is the file format for the output plots generated by OrCAD PSpice, a software I use for circuit simulations, as part of my undergraduate course.)

Having unlocked the full pack, I set forth to use the app for converting the documents at my disposal.

Some of the in-app file conversions available.

There is also a batch conversion option, that allows you to generate a multi-page PDF, or vice versa, depending upon the conversion options at your disposal. I didn’t unlock this feature, since my conversions never exceed beyond a page or two.

An experience limited by Wi-Fi

Despite the well-laid design of the app with its easy to find menus, buttons and notifications, along with the slew of conversion options it has, I was unable to enjoy it to the fullest. The main reason for this is the Wi-Fi connection at my residence, where signal strength is pretty erratic. More often than not, when trying to convert any file, I get the following message:

Check your connection and try again.

Though I couldn’t carry out conversions at all times, it has been a satisfactory experience. All the conversions worked, whenever the Wi-Fi signal was strong enough.

My thoughts and suggestions

Having used different methods of PDF conversion for a while now, I have come to realize that every file conversion requires 3 steps –

  1. Upload files to a server
  2. Wait for the server to convert the files
  3. Download the converted files

The reason most conversion apps draw flak from the users is because they falter in step 1 itself. Not everyone has access to dedicated, high-speed Internet – especially users from developing and underdeveloped nations, making it a huge obstacle that developers need to overcome.

A related moot point is the use of browser web pages for the same task. For most users, who generally have to convert only a file or two, it seems more fitting to convert in this manner, rather than use a dedicated app for the same.

Keeping this in mind, PDF Convertor can incentivize its users into continued usage, by allowing them to create an offline queue for the files to be uploaded. As an analogy, we have YouTube Offline, a feature that allows users to create an offline queue of videos, which are downloaded as and when signal strength is sufficient.

Overall, I find this app an impressive one, and look forward to improvements in its UX.

External Links

  1. PDF Convertor on Google Play; the app:


  1. PDF, What is it FOR?; a video:
  1. PDF, Version 1.7 (ISO 32000-1:2008); a technical description:


  1. Document Management – Portable document format – Part 1: PDF 1.7; the 2008 documentation:


  1. Knowing When to Use Which File Format; an article:



Duolingo – an App Review

I recently acquired a brand-new phone – a Samsung Galaxy J7, as a replacement for my previous Nokia C6-01 smart-phone. The reason is pretty simple – I wasn’t able to install any apps on my Nokia phone, since its Symbian OS is not compatible with .apk files (the file extension for Android apps).

The first thing I did with my new phone was to install a few apps – Duolingo being one of them. Since I had come across multiple recommendations for this app, I decided to give it a try. Besides, I was looking for ways to improve my language proficiency in Urdu and Japanese.

Having used the app for a little while now, I feel that it deserves a review of its own – hence this article!

The interface – first impressions

One feature I really admire about Duolingo is its UI (user interface) – clean, simple and intuitive. When the app is opened the first time, the user is greeted with a plethora of options to choose from – German, Korean, English, Russian, and Japanese, to name a few. Depending upon the user’s language preferences, it offers these languages in different instruction modes.

Since my preferred language is English, I scrolled through the section for English speakers. To my dismay, I couldn’t find Urdu listed under any section, let alone the English section. However, it did list Japanese, which I decided to try out.

The UX (user experience)

Once a course is selected, the user is redirected to a test pertaining to the language. This is completed only after correctly answering a certain number of questions, following which some XP is earned, and a few ‘lingots’ – the currency used for purchases from the ‘Shop’.

Each ‘skill’, indicated by an egg icon, comprises of a number of tests, which must be completed in a similar fashion. Each test has multiple choice questions, translation tasks (audio and/or text), and word-match questions. The more questions the user answers correctly in a row, the more XP and lingots he or she earns.

While it may be used without registration, things get a little tricky when the user wishes to save his or her progress. In that case, app registration is required.

However, once registered, users are allowed to join a language club. These clubs have weekly leaderboards, which effectively gamify the app by creating an atmosphere of competitiveness.

Improving the app

If you’re looking for an app to learn languages in the form of a casual ‘game’, then Duolingo is the way to go. However, I wasn’t quite satisfied with the app, and probably had unrealistically high expectations from it.

In order to truly learn a language, one must not only read and listen to it, but also write it, and speak it. While I don’t mind jotting down words in a notebook, I don’t know whether my handwriting is legible or not. If there was a ‘capture’ feature in Duolingo to detect and identify text, it would be a big help in improving my Japanese handwriting.

When it comes to speaking the language, it is tough to comprehend the pronunciations correctly, even with audio read-outs of displayed words. For this, I suggest that IPA transcriptions be added to every word, and get the app to read out those transcriptions. This will go a long way in making the app’s experience more fulfilling.

Edit: After publishing this post, I came across TinyCards, which is another app developed by Duolingo. Its feature of allowing the creation of custom decks by users really impressed me.

In fact, I would go so far as to say that TinyCards is the perfect learning aid I have come across, for teachers and students alike.

Here is a deck of Urdu words I created, using this app:


Related links

  1. Duolingo on Google Play; the app:


  1. IPA transcriptions in Duolingo; a GitHub repo:


  1. Recognizing handwritten glyphs; a research paper: