Why Snapgate exists
One day I looked into why my Google storage was full, and the answer was mildly embarrassing. Not holidays. Not birthdays. Parking tickets, receipts, my car's bay number on level 3 of an airport, a hotel wifi password, a shirt size, a whiteboard from a meeting that ended eighteen months ago.
Photos I took to look at for ten minutes, paying rent in my account ever since.
The problem isn't the camera, it's that Google Photos decides by folder
Google Photos backup is switched on or off per folder, and it lets you upload single photos by hand. But everything I shoot goes into the same camera folder: the holiday photo and the parking ticket. Either both go up, or neither does and I accept the risk of losing the photos that actually matter.
Since picking by hand afterwards never actually happens, most people leave it on and pay to store rubbish. It is a perfectly reasonable design from Google's point of view, and a perfectly annoying one from mine.
There are only two ways to fix it
The first is to review your camera roll periodically and delete by hand. It works in theory. In practice nobody does it, because it is a chore with no immediate reward that can always wait until tomorrow.
The second is to decide in the moment. When you photograph a receipt, you know perfectly well you don't want it forever. That information exists precisely then, and evaporates thirty seconds later. Snapgate is nothing more than an attempt to capture it before it's gone.
What I learned building it
The first version asked photo by photo with a notification. It seemed obvious. Then I took six shots of the same plate and got six notifications, and understood that the obvious design was the wrong one.
The version that survived groups them: a single notification that rewrites itself, with two buttons inside. You decide without opening anything, and a burst is still one interruption. It's less elegant to explain and far better to use.
What Snapgate does not solve
Worth being honest: this app stops your cloud filling up, not your phone. The receipt photo you discard still takes three megabytes on the device. At one point I considered adding expiry — marked photos disappearing on their own after seven days — and deliberately left it out.
Deleting is irreversible in the user's eyes, even when it technically goes to the bin. If an app gets it wrong once and a photo that mattered disappears, you uninstall it forever, and rightly so. I would rather ship an app that does less and that you can trust completely.