The Quality Index boasts over 100,000 reviews from websites like 148Apps, Pocket Gamer, and Tapscape, and uses a unique metric to create a single definitive score for each iPhone title.
For anyone who doubted whether Aussie studio Halfbrick could reproduce the immense success it enjoyed with Fruit Ninja on the App Store, look no further than Jetpack Joyride's lofty position on the Qi rankings for September.
That's not to suggest the rocket-propelled Barry Steakfries had it all his own way this month - RedLynx and Chillingo's highly polished line-drawing sim DrawRace 2 almost overtook Jetpack Joyride on the final bend, while the similarly speedy Grand Prix Story couldn't quite complete a fairytale F1 finish for its Japanese constructor.
Proof once more that good things come in small packages on iPhone, meanwhile, as Tiny Invaders's and Tiny Heroes's 'miniscule' names belie their big ambitions.
Qis Top 10 iPhone games of September 2011
| Pos. | Game | Qi rating | Reviews |
| 1. | Jetpack Joyride | 9.1 | 10 |
| 2. | DrawRace 2 | 9.0 | 7 |
| 3. | Samurai Bloodshow | 8.4 | 4 |
| 4. | Muffin Knight | 8.3 | 7 |
| 5. | Pocket RPG iPhone Edition | 8.3 | 3 |
| 6. | Grand Prix Story | 8.1 | 6 |
| 7. | Tiny Heroes | 8.1 | 6 |
| 8. | NFL Rivals | 7.9 | 9 |
| 9. | Tiny Invaders | 7.2 | 5 |
| 10. | Frogger Decades | 7.0 | 6 |
N.B. While we only display the average score to one decimal place, the list is generated to further significant figures. We just don't show them all.
And, naturally, this is a static graph based on live listings which are subject to constant change as new releases and reviews emerge.
In order to provide a regular marker of the critical zeitgeist, however, we will continue to round up the best of the iPhone games released each month to provide the definitive Quality Index top ten.
Quality Index
