Injustice is a great game, but it differs vastly from infinity blade 3. Injustice is a street fighter type game, and has a roster of characters. It does have the infinity blade swipe system, but its used to build up your power attacks or land combos. When i played injustice it got so hard to the point where it was unbeatable without paying, so keep that in mind, but then again they could have fixed it, since i haven't played it for a long time.
If you don't have it already download the first episode of Lone Wolf (currently free). It is a game book but has IB like fight sequences. In fact I liked the fighting in it so much that I deleted IB3 from my device as Lone Wolf scratches that same itch for me. Second episode just became available this week so now is a good time to get on board.
Epoch 2 is the current IGN free game of the month. It's a hooting cover game rather than swords, but I think it scratches the same itch as Infinity Blade.
I bought it during the $2.99 sale and haven't really played it. I just played a few minutes for impression. Fun like the first one but i'm currently sticked to TWEWY