Show HN: I built a tool to sync localStorage between devices

At my day job, we have a daily async stand-up. We have to message a slack bot how many hours we have worked on a given task that day and overall.

The format is:

> Task: "Task Name" | Worked: 5h Total: 16h > Description: Finished implementation of feature.

I don't complain. Most fully remote jobs come with a version of this, but doing it manually got tedious. So, I needed a simple app that would track this.

I am not usually a fan of "vibe coded" apps, but this was an ideal candidate for it, since it's not production code. Most LLMs solve the problem by creating a single HTML file with forms that save data to localStorage. This was perfect for me - no hosting, no DB, no backend. Just 15 mins of prompting.

One day I was outside, just with my phone, and of course I couldn't use the app. I thought "how hard can it be to synchronize localStorage data across devices?". Turns out, it's not that hard, if you are ready to build a whole platform around it.

https://htmlsync.io does just that. You upload your HTML app that works with localStorage and get a subdomain for it. The tool automatically synchronizes your changes across devices. You can create private and public apps, can decide which keys to synchronize by using the "no_sync_" prefix. The "public-hidden" CSS class can be used to hide UI elements in public view. You also get a subdomain for your profile where all your apps are listed for easy access.

I hope you find this as useful as I did.

I'd also appreciate your feedback if you end up using it.