In the UK, there are many photo booths, which also give you a reference number along the prints, which you can provide to the home office as part of the passpor

In the UK, there are many photo booths, which also give you a reference number along the prints, which you can provide to the home office as part of the passport application so they get the digital copy from the photo booth company. Though I am sure there must be hundreds of photo booth apps already.