Walk through the place with EverStamp when you move in and again when you move out. Every photo carries the date, the time and the address in the image, an independent service timestamps the file, and whoever decides about the deposit checks it in the browser.

A folder of phone pictures says nothing reliable about when they were taken. The other side only has to say they are from later.
The argument is always about the one carpet or the one wall that is not in the pictures, because nobody walked through the place in order.
Check-out comes a year or more after check-in. By then nobody remembers, and the photos are all anyone has.
Since 1 May 2026, most private tenancies in England are assured periodic tenancies. The deposit still has to be protected in one of three government-backed schemes within 30 days, and each scheme offers a free dispute service. If landlord and tenant both agree to use it, both are asked for evidence and the decision is final. That evidence is where check-in and check-out photos come in.
Sources: gov.uk, Tenancy deposit protection; gov.uk, Disputes and problems
The Pre-inspection template in the app walks you through it: living room, kitchen, bathroom, bedrooms, meter readings and keys, with a minimum number of photos per room. At check-out, the Final inspection template adds damage and the keys you hand back.
A required step has to be there before the file closes, so a forgotten room shows up while you are still standing in it.
Room by room. The stamp bar goes into every photo, and the app carries on in a cellar with no signal.
An independent service timestamps the whole series. From then on, a photo added later or a changed pixel shows up.
As a PDF report, the archive or a link. At check-out you do the same again, in a second file.
They open the file in the browser, with no account and nothing to install, and read in plain words what was recorded and when.

No. They open the file or the link in a browser. Only the person taking the photos needs the app, and Basis is free for one file a month.
Yes. One file per moment works best: the check-in is sealed on the day you move in, the check-out on the day you leave, each with its own timestamp.
The app carries on. Every photo is signed on the phone straight away, and the file is sealed once you are back online. The file shows how wide the window between capture and stamp was.
The date on an ordinary photo comes from the phone and can be changed afterwards. Here the time that counts comes from an independent service, and the page shows the window between the photo and the stamp.