Yes, you can use the external app image widget to do exactly this. It will launch your specified external app on the phone - instead of the default camera - which you can then use to take a photo, mark it up with timestamps, GPS, etc, and save to the phone’s gallery. A followup image question can then be used to fetch this image from the gallery.
This is an example form that uses the popular Open Camera to acquire the image.
ExternalCamera_appearance.xlsx (14.4 KB)
Note, there is also newer approach to accomplish basically the same, via specifying an app parameter instead of the ex:... appearance. This is supported in KoboCollect today, but unfortunately it requires a newer version of pyxform to deploy a form using it [so if you try it today you will get a deployment error]. However, this will be fixed shortly as we are rolling out a new version of pyxform in the next Kobo release, at which point you can use either approach.
