I've got it working on Nexus 5 (lollipop), no crashing, no rooting, no decompiling. However it does require using ADB to change your phone resolution (ADB is an official google tool for android development)
1 Download korean APK http://www.mediafire.com/download/7bt0kr0hs66qf4k/%ED%95%98%EC%8A%A4.zip (from korean play store i believe, not modified in any way - Game will play in english don't worry)
2 Copy OBB files to Android/obb/com.blizzard.wtcg.hearthstone as usual
3 Sideload the apk (using airdroid (from appstore) or adb or any other method)
4 plug phone into computer and run "adb shell wm size 1440x2560" in command line (use google to figure out how to install adb)
5 run hearthstone!
I've only tried this for Nexus 5 lollipop, may or may not work for others
Your phone will look weird (wrong resolution) until you either restart it or run adb shell wm size reset
Alguien me puede traducir los pasos? Me pierdo con algunas palabra sueltas ^^