You may need to take a break from the usual phone and tablet tasks – email, social networking, gaming, messaging – and actually make something productive. If you need to edit files on the go, whether it's audio from an interview or a PDF sent from the office, these are the apps you need to have on hand, or the sites to which you have the browser
It is quite possible that other people will send you files that are in common Microsoft Office formats (such as .docx for Word , .xlsx for Excel and .pptx for PowerPoint) This can cause problems if you try to open them without a corresponding app on your phone.
For example, the Apple Mail client for iOS can open basic versions of them, but it will confuse the formatting and not allow changes. Gmail for Android and iOS will be better at previewing, but you will not be able to make any changes. Instead, you'll be directed to the official Microsoft apps (by the way, Dropbox if you try and.) Open Office files in this app.
The mobile versions of Word (Android / iOS), Excel (Android / iOS) and PowerPoint (Android / iOS) are obvious apps that you can access when you receive many office files sent to your phone or tablet. You get a perfect preview of your files. If you're on a device with a screen less than 10.1 inches in size, you can also make changes if you have a free Microsoft account.
If you have a large tablet or do not want to set up a Microsoft account, everything is not lost. You can use Apple's own Pages, Numbers, or Keynote apps for iOS to import and edit Office files. However, some formatting errors may occur. Similarly, Google Docs (Android / iOS), Sheets (Android / iOS), and Slides (Android / iOS) can open and edit Microsoft Office files, although formatting and layout may not be perfectly preserved.
In the context of Office files, you may receive PDFs on your phone or tablet that need to be edited or edited before you can access a computer. IOS wins, allowing you to annotate, edit text, add signatures, and more to PDF directly from your inbox or iCloud Drive without the need to install other apps. Just tap the pencil icon in the upper right corner of the preview screen.
With Android, you can easily view PDFs from any application in which you received them. If you want to make changes, you will need another application. One of the most important options is Xodo for Android and iOS (free). Here's what you'll need: annotations, completing PDF forms, support for digital signatures, easy integration with cloud services, and more.  If you'd like another option, Foxit MobilePDF is also available for Android and iOS ( free) recommend. It does not have as many features as Xodo, but you can annotate, stamp, and sign PDF documents with the app, as well as convert files between PDF and various other common file formats.
While this is not as common as with Office files, it can happen that you need to edit an audio file with your mobile device. The Freemium MP3 Cutter for Android is an obvious choice when traveling with Android and MP3 files – it offers a user-friendly layout, simple cutting tools and a built-in option to set a file as a ringtone.
The Hokusai Audio Editor for iOS (Freemium) has earned many fans on Apple devices. It includes editing of multitrack tracks, filters and special effects, a selection of import and export options and integration with various cloud services (including iCloud and Dropbox). It's almost as far as audio editing on a phone or tablet. TwistedWave Audio Editor for iOS ($ 10) is also worth mentioning: it's packed with features and effects that are not as intuitive as Hokusai's.
In terms of cross-platform apps, we like WavePad Audio Editor for Android and iOS (Freemium), which largely sticks to the fundamentals of audio editing and effects, but masters them well, and Lexis Audio Editor for Android and iOS (Freemium) which are not the most sophisticated options, but do simple edits very easy.
You're probably already familiar with editing pictures on your phone, even if they're just the default options for photos (iOS) and Google Photos (Android) handset. Apple and Google have gradually added more features to these tools, and they're now good enough that most users probably will not need a third-party app.
Moving your mobile photo edits to the next level allows you to do everything with Adobe Photoshop Fix for Android and iOS (for free), from distorting objects in images to lightening shadows. You do not need to be a Creative Cloud Subscriber (subscription service from Adobe) to use the app, but you can save files in the cloud when you are.
Google-developed Snapseed for Android and iOS (free) is another great mobile picture editor that combines a variety of editing and customization tools for your photos and is relatively easy to use. Afterlight for Android and iOS ($ 3) is also one of the best options here, from Instagram filters to advanced color curve management to make your photos look great.