Last year, the company generated some buzz when it launched a Mac app that records on the system in a compressed video format everything you do during the day — the app only works on Macs with Apple Silicon. Later, users can ask very specific questions, such as who said something in particular during a Zoom meeting. Rewind can also be used to find a website you visited on Chrome based on the content of the page. The startup said that it processes everything locally on the system.

Now, Rewind is going down a similar path with its iOS app. However, it currently records activity just on Safari. You also can go to settings and ask the app to not record anything on specific pages. The company said that if you want to add stuff from other apps, you have to take a screenshot, as Rewind imports screenshots automatically.

Rewind uses text recognition so you can search for specific terms to find screenshots or whatever you browsed on Safari. The app also has a GPT-4 integration, so you can ask questions like “Who mentioned Twitter last week?” or remind yourself about how you know someone.

The app uses the same compression algorithm that it uses on the Mac to compress raw video recording data up to 3,750x. That means the data takes up little space on the phone.

When a user asked about how Rewind, an app that constantly records activity, eats up the battery, the company’s co-founder Dan Siroker posted a screenshot showing the app had consumed 4% of battery in the last 24 hours on his device. However, the app might behave differently for people using Safari more on older iPhones.

Rewind told TechCrunch that it only captures info that changes from frame to frame. Plus, it has built algorithms for Apple devices to reduce power usage.

The company said that all user data is private and is not sold or used to train AI models. In a tweet, Siroker emphasized that all recordings are stored on the device and no one else has access to them. Despite these claims, a lot depends on how the startup proves itself by maintaining user privacy at the highest level. Especially, when it is asking users to allow the app to record their activity.

Rewind has raised $10 million at a $75 million valuation from investors like a16z and First Round Capital. Initially, the company’s Mac app was free, but now it has capped free usage to 50 Rewinds and introduced paid plans for more access. The company counts one session of traversing through history or searching as one “Rewind.” One question asked through GPT-4 also counts as a “Rewind.” The startup said that at the moment it wants to keep the iOS app free “for as long as possible.”