Hiya,
I’ve found out about Evinced accessibility tool recently, thought it was interesting 
https://www.evinced.com/products/iOS/
We haven’t tried it just yet but it seems to have a nice ability to generate accessibility reports for iOS applications. 
https://mobilea11y.com/ looks like a nice little site with some great posts on accessibility. Again seems to be mostly iOS focussed but I’ve learned a fair bit by reading through some of the posts!
(Some Android stuff I’ve found on there too… but not a lot!)
If you have come across any tools, please feel free to share.