This has been discussed before, so if you search you may find some lenghty threads on the topic. But a short summary is: The data you see on iFly is pretty much exactly what the FAA is broadcasting. It's blocky because the broadacsts have limited bandwidth.
Other EFBs "massage" the data to make it look smoother/prettier. They're not making the data any better, they're just making you think it is. However, that takes processing power. iFly is designed to run on a broad range of hardware platforms, and AP is trying to maintain support for many relatively old hardware platforms and new-but-inexpensive platforms that may have limited processing capability compared to modern and/or high-end gear. To maintain good performance on those less-capabile platforms, the software does minimal processing on the data before it's presented to the user.