The Office software for Android OS will come in handy if you want to view or edit any document or other file, and you have only a tablet or smartphone.

Textfee 3.1.3

Documents Scanner: Textfee 3.1.3

Silver medal
Android 4.0.3 and higher   English   29.2 MB (APK-installer in SFX, without dictionaries)
Free application to scan documents using the Android-based devices.
EBookDroid 2.6.0

Reader: EBookDroid 2.6.0

Golden medal
Android 4.4 and higher   English/Russian   12.4 MB (APK-installer in SFX)
Universal free e-book reader for Android.

Spellchecking system from