VidX is a free, open-source 4K video player for Android phones and tablets. It supports all formats and plays all kinds of videos, from local to streaming. It is an ideal video player for both phone and tablet and offers the best user experience. It also allows you to add subtitles, closed captions, and even download subtitles for offline playback.

VidX is an open-source project, which means that the source code is available to everyone and you can make changes and improvements to the software. All the changes are available under a GNU General Public License.

VidX supports all formats, including MKV, MP4, AVI, MOV, OGG, FLAC, TS, M2TS, Wv, and AAC. It also supports closed captions. It has support for multi-track audio and subtitles.