Is anything stored outside my device?
No, there's no data going anywhere if you don't export it
Do I need to be online when I use the app?
Only if you need to download a species list or one of the alternative layer systems. You can't look at maps if you are offline unless you have a cached map.
Will there be a version for iOS?
Probably not, sorry.
Are photos exported with my project?
No, photos need to be handled separately.
How to deal with permanent plots?
Vegapp does not distinguish between plots and plot obervations but you can assign a "Permanent Plot ID" to your observation
Can you provide me with a species list for my area?
You can ask via greens [at] vegapp.de but we cannot promise anything. The chances are higher if you have a synonymized checklist along with a valid citation for the list and a license that allows that usage.