monday CRM - monday sales CRM is a customizable customer relationship management software for every business with support for unlimited leads and accounts and prepaid plans.

GumHub - Sell access to your GitHub repos with Gumroad

Composity - Composity is software solution for more efficient business! CRM, Inventory, POS, Invoicing, Financials and Accounting, Sales and Purchase modules, Document management, Website and eCommerce

Pixi.js - Fast lightweight 2D library that works across all devices

Bigin by Zoho CRM - Pipeline-centric CRM built and priced for small businesses

Gumroad Memberships - Earn your audience's ongoing support