Collabora Office

Collabora Office (formerly known as LibreOffice Viewer) is the official app for the popular open source word processor that lets you open any office document right on your Android device.

The app supports a long list of formats, so you can open any document with any of the following extensions: .odt, .odp, .ods, .ots, .ott, .otp, .docx, .pptx, .xlsx, .dotx, .xltx, .ppsx, .doc, .ppt, .xls, .dot, .xlt, .pps. This means you can open any document created with OpenOffice or Microsoft Office.

Collabora Office is a good text editor that's continually under development and being improved. Even though its features are a bit limited right now, the number of different formats it supports makes it an app to keep in mind for all those who frequently use text documents on Android.