It's called LiteRadar — https://literadar.com

It’s: - 100% free, with no ads - Ultra-fast - Beautiful visuals with smooth 60fps animation

Weather radar apps make you look at ads, use a specific device, and hit paywalls to get at data that is freely provided by NOAA. On the other hand, the NOAA pages are ugly and unpleasant to me. So, I went on a side quest to build a weather radar experience I actually wanted to use.

I wouldn’t run this service if it weren’t insanely cheap to run. After some careful optimization (with the help of Fable 5), I was able to fit it comfortably in the free tiers of Modal, Cloudflare, and Vercel. I can offer it to everyone for free, no-ads. I guess this could change if it really blew up, but I doubt that will happen.

Here’s the core trick. I was frustrated with the jankiness of traditional radar imagery. I had to fix it. In this app, we interpolate radar imagery in real time on the GPU with optical flow samples around each radar time increment. The shader approximates Lagrangian advection—not a perfect weather simulation, but reasonable for 2 minute interpolation. This means you can scrub the slider and get a silky smooth animation. Yes!

How it works. NOAA publishes MRMS, a free composite radar dataset in two-minute increments—the same underlying public data many radar apps use. LiteRadar processes each new frame with a hyper-optimized Modal job that generates map tiles and computes per-frame optical flow. After optimization, the pipeline became mostly I/O-bound, taking about 4-5s every 2 minutes to handle the entire US.

The tiles are packaged as PMTiles for fast range requests and stored in Cloudflare R2, where egress is free. The frontend is a single-page Next.js app on Vercel.

Try it: https://literadar.com