Describe the functionality you would like to see.

I would like to add support for the NanoMegas Topspin app5 file format, which is a software/system by which 4D STEM data can be collected.
A handful of open-source readers already exist, but none that gel nicely with hyperspy.

Describe the context

To my knowledge, there is no need for a writer, only a reader.
I would like to try writing a reader and submitting a PR myself, but wanted to open an issue first in case there was any reason I shouldn't go down this route.

Additional information

I have some phony data I can use, and have skimmed through the contribution section for hyperspy and RosettasciIO so I understand the basic requirements, though I've never contributed to either project before now.

Some details on the tool itself:
https://nanomegas.com/all-in-one-topspin-platform-for-precession-advanced-analytical/