"Estate sale app" isn't one product. It's three categories. Confusing them is how you end up paying for something you don't need.
Category 1: Discovery platforms
EstateSales.net is the dominant one — since 2002, thousands of companies, faithful native iOS/Android apps. EstateSales.org and Estatesales.com are smaller aggregators. If you want to find sales, start here.
Category 2: Line reservation tools
Pickerty is the original reference model: claim a spot online, show up at your assigned time. EstateEntry implements the same idea plus a door check-in QR code, no-show auto-backfill, and a similar advance reservation mental model. Estate Sale Connect and EstateScale both ship digital line/queue features as part of bigger operator toolsets, and EstateSales.net has native Line Management if you already publish there.
Category 3: Operator back-office
EstateFlow handles inventory photography, AI-assisted pricing, and pushing listings to EstateSales.net. Not a line tool; competes for your attention and budget separately.
What NOT to use
Generic restaurant/queue apps (Waitwhile, Qminder, etc.) don't know multi-day sales, category filtering, estate-sale-specific photo listings, shopper accounts, or the realities of a residential driveway. A sales-savvy company could repurpose one, but it'd mean missing features you can't bolt on.
Real recommendation
Most shoppers want EstateSales.net + a line tool the company happen to offer. Most companies want the workflow plus the yard-sign QR promo, which is what dedicated line products (EstateEntry included) are built for.