This app was mentioned in 2 comments, with an average of 3.00 upvotes
have you tried this? https://play.google.com/store/apps/details?id=com.anforapps.camerasuperpixel&hl=en&rdid=com.anforapps.camerasuperpixel
i get pictures with higher resolution with this camera, however i am not sure that the quality is actually better. (on oneplus 5 btw)
update: i reinstalled it. i am getting 18mb pictures with 63.7mp, but with only a modest increase in detail, do try and tell me your results
This: https://play.google.com/store/apps/details?id=com.anforapps.camerasuperpixel
Android Central made a post about it.