Pixel Studio Pro is a pretty popular mobile pixel art app. It supports importing .aseprite files, but because there’s no easy way to reimport Pixel Studio files back into Aseprite (apart from exporting each layer as a seperate png), it really limits PS as a good mobile pair with Aseprite.
Would love to see .PSP and .PSD import support for Aseprite in the future, to make pixel art edits on-the-go much simpler!
I know this is a hell of a necro response!
But PLEASE either this or an android version please 
An Aseprite Android app would be my ideal scenario, but being able to read .psp files from pixel studio or even .psd files would be great for my workflow in lieu of that.
As far as I know (I’ve never used Pixel Studio Pro) the format is closed (?). I’m not sure if there is a public spec (and probably that’s why no other users created an extension to do this). Or probably it’s a .zip file, but I don’t know about this format and never used .psp files.
In any case I’d prefer if this is created as an extensions.