Battleheart Legacy.....It is a great game with superb combat with lots of class combination and different types of skills. You can have a bit of ninja skills along with a bit of necromancer skills with a bit of warrior skills.....there are new about endless possible combination of class skills and therefore lots of replay value to. You can play as a different person with different powers in every replay....

Wayward Souls....it is a rougelike with randomly generated levels...it is a really fun game where you have to try again and again...the combat is simple but with a certain depth to it. It is not mindless hack and slash....you have to give a focus, and have proper timing....with different types of enemies it can be quite fun.

There is also Implosion: Never lose Hope if you don't need many rpg elements...but just simple leveling up and some upgrade items....Implosion is a solid hack and slash game and probably one of the best.

You may also try Quadropus rampage.....this game is supposed to be repetitive but strangely it never felt repetitive. It was really fun to play and quite addicting too. With new weapons, loots, different modes it remains fresh....

Then, there is this game called 'Dark Slash'.....it is more of a mini game with minimalistic controls but not bad at all...

Also, there is 'Only One'....while the game may not seem much with just one stage where you keep on killing enemies....it does gives you power items with which you can upgrade and get new powers and even if the combat is not flashy.....unlike many of those arcadey mindless hack & slash games needing bare minimum skill, the combat of this game has a lot of depth requiring skill and strategy....and that is why it doesn't really ever feels repetitive.

There are lots of other ARPGs like Zenonias and stuff but many of them requires online connection and I haven't try those games.

If you more high quality games you may get ppsspp (psp emulator) and some psp games on your phone like monster hunter freedom unite, kingdom hearts birth by sleep etc.....those are the best of the ARPGS you can play on phone