Invoryn is subscription inventory software for independent retailers, parts stores and suppliers. Low-stock alerts are on every plan. Phone-camera barcode scanning and purchase orders are on Pro and above, and multi-location tracking is on Business.
Plans are Starter $29 a month, Pro $79 a month or $790 a year, and Business $149 a month or $1,490 a year. There is no free tier, but a demo can be explored without an account. It lists integrations with Square, Shopify, WooCommerce, Lightspeed and QuickBooks Online.
I wanted to make inventory management simpler and easier for businesses.