Wapsi
Add a "Notify me on WhatsApp" button to sold-out product pages. Wapsi messages each waiting shopper the moment stock is back so they can buy again.
The pitch, and what the numbers say
Wapsi: WhatsApp Restock Alerts — Stock alerts · https://wapsi.app/
Estimated revenue: reviews × installs-per-review × paying share × entry price; every input is on the full x-ray.
Why users leave
No negative review of Wapsi has been read yet, so there is no complaint breakdown and no build idea. Review sources are checked weekly.
Closest alternatives
- Back In Stock ‑ Notify Hero$42–279
- Essential ‑ Back In Stock Pro—
- A1: back in stock$586–4k
- プライシー再入荷通知$94–630
- WC Wishlist & Back in Stock$1k–7k
Who is buying right now
No public buyer thread in the same market in the last 30 days. The scanner runs every 15 minutes.
Full 1-star breakdown with verbatim quotes, the build blueprint and every live thread — on every product.
How to read this
Sources: the product's public listing and reviews, its published price, and public forum threads. Revenue is an estimate unless marked verified by the founder; the formula and its inputs are on the full x-ray. Complaints are grouped by a language model and each quote is a verbatim excerpt, linked to the original review. Build difficulty is a model's reading of the listing and the complaints, not a measurement. Figures are a snapshot of Oct 31, 2026. Corrections: corrections.