...but you probably won't be able to take advantage of them because native Push Notifications are still in beta so developer Iconofactory had to limit the much-needed feature to the first thousand users, as determined on a first-come, first-served basis.
The system is very similar to the reservation tickets in the Mailbox app. Luckily, I was able to reserve my spot on time so my copy of Twitterrific version 5.2 has native push alerts turned on.
Tucked away under the app's settings, push alerts can be turned on and off individually for direct messages, replies, mentions, favorites, retweets and follows.
Another handy treat: each of these can be color-coded so you get a better idea of a particular notification's importance after it appears on your screen, especially handy when these alerts start cropping up on your Lock screen...