Then there's XInternalSD which does exactly what I need except few things (requires unnecessary setup) which is why I am coming with my own version of similar module.
Module Obb on SD attempts to make it seamless - just enable module, reboot and move obb's to SD card (to same folder: Android/obb) - that's it. No need to enter any path or whitelist/blacklist any app. Do you want to only move Obb from Grand Theft Auto? Then only move that obb. Obb on SD will detect "obb on SD" and enable hooks only for this single game.
I tried various approaches. For example hooking up constructors of File() but since most of large obb's comes from games - ane they are native, it doesn't really work. I just like to have elegant and efficient solution which I thing this module is.
Need more features or move other directories? Than use FolderMount, GL to SD or other app.
Compatibility? It should be the same as XInternalSD. Almost all games I have work just fine (Rockstar, Gameloft, EA, Sega and others), the only trouble I encountered was with games from DotEmu which had hardcoded path to /mnt/sdcard from within native libraries (and it's outside of scope for Xposed to change such fopen call).
Obb on SD also tries to make Play Store update OBB files directly on SD card. It works during my tests but I hear some have issues with it. If you do, you might want to use the "no_play_store_hooks" version instead (available only from here). EDIT: Since version 0.4 there are configuration toggles for enabling/disabling Play Store hooks.
Download: Xposed Module Repository or Play Store
v0.4.2 (20160117) - Report internal memory path in Settings (including a workaround for related issue). - Add ad banner. Sorry for this but it's the way to keep the app free while be able to provide future updates. There's an option to purchase a single key to hide ads across all of my apps. v0.4.1 (20160103) - Add option for Android (5 and) 6 support (needs to be enabled manually) v0.4 (20151226) - Add settings screen v0.3.2 (20141206) - Allow Google Translate v0.3.1 (20141018) - Exclude first party apps (Android/Google) v0.3 (20141007) - beta - Add support for Obb on SD updates/removals via Play Store - Bug fix v0.2 (20141002) - experimental - Add /Android/data support v0.1 (20140922) - Initial version