In a digital office environment, PDFs will become the new normal, replacing paper.
While a 'PDF Editing' software is used to make the PDF work-ready (by performing CPBH), a good 'PDF working' software is also essential to conveniently work on PDF files. I briefly dealt with this topic in Office 1.0. However, I later felt that the subject requires some explanation and hence this post.
The difference between a 'PDF Editing' and 'PDF working' software is mostly relevant for iPad users. If you directly work on your desktop/ laptop (be it on Windows or Mac) or your Microsoft Surface, you can use the same software for all purposes (with most prominent PDF Editing software; read the below features, especially 1 and 4, for confirmation).
However, apart from its advantages, iPad has its disadvantages since it is a mobile OS. Therefore, it is essential to select a good 'PDF working' app for iPad.
Though I never used an Android tablet, in my opinion, this post will also be relevant for android users (subject to correction by android users) because android is also a mobile OS.
Please note that I refer to iOS apps in this post. Non-iPad users may ignore such reference and only concentrate on the requisite features.
1. THE APP SHOULD RECOGNISE PAGE-LABELLING
All PDF apps do not recognise page-labelling. Even some widely used apps such as 'iAnnotate' and 'LiquidText', in their current form, do not recognise page-labelling.
If you currently use iAnnotate or LiquidText, you might be navigating through the file using 'bookmarks'. However, once you get accustomed to page-labelled PDFs, thus being able to instantly flip to a target page, you will find it very difficult to work on these apps.
I understand some of these apps contain enthusing features (especially LiquidText). However, in my personal opinion, recognising page-labelling is peremptory for long term functioning, especially on PDF case files. In fact, LiquidText does not even have a 'go to' page option.
2. THE APP SHOULD CONTAIN INTERNAL MECHANISM TO LINK TO A CLOUD STORAGE
iOS has a deficient user interface with respect to folders/ files. On desktops/ laptops, one is generally accustomed to the following working pattern:
You open any folder;
You open the target file with your preferred software;
You can also open multiple files, in as many windows as you want;
You work on the file(s);
You save the changes; and
You close the file(s).
Unfortunately, the above pattern will not work in iOS. Even after the iOS 11 update with 'files' app, existing iPad users might be cognizant of the following difficulties:
Though you can reach any file in your 'files' app or the respective 'cloud storage' app, you can only preview the file or open it with a system configured app.
If you want to open the file(s) in a different app, you need to 'export' the file(s) to the respective app.
Many times, the changes you make to a file after you export to an app (other than the system configured app) will not be saved in the source file as a different version of the file is created, each time you 'export' the file.
Your ability to open and toggle between multiple files at the same time is also extremely limited (depending on several factors).
To obviate all these difficulties, your PDF app should contain an internal mechanism to connect to any cloud storage along with an option to open multiple files at the same time.
Please note that an internal mechanism does not mean a mere button to in turn open the 'files' app. For example, in LiquidText, on the top left corner of your app, you have an option to "open file", which will open the 'files' app. This will not suffice.
Working through a mere redirection to the iPad's 'files' app is still subject to all the above shortcomings.
Therefore, any app you choose must contain a feature for direct linking to your cloud storage.
3. THE APP SHOULD HAVE INTERNAL SELECTIVE SYNC
Apart from an internal connection to a cloud storage, the app should also enable you to store any folder/ file locally for offline functioning ('selective sync').
No one can have continuous internet connectivity. Even if you have good connectivity, it takes time to open file(s) stored on cloud. If you decide to argue a matter or brief another counsel with your iPad, you will obviously not have time to wait for each new file to be opened.
At the same time, you cannot save your entire office on your iPad. Apart from space constraints, it will lead to humongous data wastage.
Therefore, 'selective sync' feature is required to keep specific folders readily available.
Folders you selectively sync are not only available offline but are also simultaneously connected to the cloud (called as a 'two-way sync'). With this feature, you need not wait for the file to be downloaded for opening it. Moreover, any notations/ changes to a synced file in a no-internet zone will automatically get uploaded to the source file once you are reconnected.
Please note that most cloud storage apps for iPad, including DropBox and OneDrive, have options to keep folders/ files offline (which is also a selective two-way sync). But, even with this option, working on such files is still susceptible to all the drawbacks in iPad's user interface mentioned above.
Therefore, the PDF app should have this functionality internally within the app.
4. THE APP SHOULD CONTAIN MULTIPLE ANNOTATION AND COMMENTING OPTIONS
Most apps easily qualify this criteria. PDF apps are primarily built for annotations and commenting. Therefore, most app developers do not leave their apps deficient in this field.
Just ensure that the app has the required annotation and commenting options you prefer.
5. THE APP SHOULD HAVE BASIC PAGE ORGANISATION TOOLS
Even after cleaning the PDF, you are often confronted with situations wherein you are required to add, delete, move, change the orientation of pages, etc.
Therefore, your app should contain basic page organisation tools.
6. THE APP SHOULD RECOGNISE BOOKMARKS AND HYPERLINKS
Though important, I mention this feature at last because most PDF apps contain this function. Just ensure your app is not deficient in this regard.
CONCLUSION
In my experience, the only app satisfying all the above criteria is 'PDF Expert'. PDF Expert also has a simple user interface for easy operation.
Please note that off late (since its upgrade from 'PDF Expert 6' to 'PDF Expert 7') the app has been erratic in its functioning despite its heavy price (a recurring annual cost of Rs. 4099/-). Though the developer has been continuously updating on the App Store that they are working hard to remove the glitches, it is still susceptible to frequent aberrations.
I have searched to the best of my ability, in vain, to find an alternative. I tried paid premium versions of iAnnotate, LiquidText, Foxit Reader, Adobe Acrobat, GoodReader, PDF viewer, iLovePDF and half a dozen other apps in this segment. None of them satisfy all the above features.
Please let me know if you are aware of any app satisfying all the above enumerated features, (especially the first three).
In my opinion, it is worrying to depend on a single app in this segment for working on iPad. In fact, Apple should develop a good PDF app in-house considering the importance of PDFs in professional use.
PS: Through out my blog, I strongly recommend 'Adobe Acrobat DC' as the best PDF Editing software for advocates. However, when it comes to working on PDFs (on Windows and Mac), it is highly disappointing for lack of effective annotation and commenting options. This could be remedied with certain plug-ins, which I will deal with in a separate post.
In iPad, I strongly advice you to stay away from 'Adobe Acrobat' app. It is extremely basic without any effective features.