Subtitles on iPad/iPhone

I'm planning to build a linux box with Serviio as media server for music and video. I tried it on a virtual box installation and it works fine, but before I move it on my actual media server I'd like to clarify a doubt. I often watch movies with subtitles, so is there anyone who knows for sure if there's an app (like PlugPlayer or AirPlayer) which can handle subtitles (.srt) without problems?
I tried some lite versions (media:connect and 8player) but they don't seems to handle it (maybe bc they are lite...). I'd really like to know it before buying any single streaming app in the App Store

Thanks in advance
