For English app, pls google PopcornTime or xBMC/Kodi.

For chinese apps, try the below link :
http://down.znds.com/apk/tool/2014/0806/956.html

To meet your requirement, need combination of few apps. I could preinstall the combination for you Because uyour internet only 4Mbps yyou might not able to have have smooth HD streaming, you could choose SD resolution. Alternatively when your line is too slow yyou can download and watch later.

For elder parent, I would advise to subscribe to paid IPTV service like cloudtv which more easy to access and some level of service warranty.

KODI is pre-installed .If you have budget constraint, H8 should be sufficient. If you could affort, I would advise Q16 Quad Core.