Let's check the odds for different hands.
The odds of the hands you mention with seven cards are like so.
Quads 594 : 1
Full House 37.5 : 1
In 73 hands it is not unreasonable to see full house twice. The quads are a little unlikely, being 73/594. It is unlikely but not grotesquely so. Very roughly 1 in 8.
In order to check you would have to do a much more extensive statistical examination. You would need several thousand hands at least. You would need to record every hand and see if they were distributed in a manner consistent with randomness. It would not be sufficient to observe a few "outlier" hands and conclude anything from that.
Unless, that is, you consistently started seeing quads at one-in-73 or so frequency. If you had the app deal, say, 10,000 full Holdem hands and got quads in the range of (very roughly) 20 times, then it is reasonable. If you got quads 160 times then you could be fairly confident that the app was fubar.
Possibly you can get the app to interact with a script and do the dealing without humans having to play the hands?