I am looking for a phone app that would allow me to add notes and dimensions to a photo.
Since there is no exact application for this process, I recommend using Adobe Lightroom mobile. The application acts as an image editor with the possibility to add text. For the dimensions request, use the image properties to get the size, then activate the type tool and input the dimensions of the picture. There is no automated way to do it.
Browse the application's page at Play Store to download it: https://play.google.com/store/apps/details?id=com.adobe.lrmobile