Validated ideas - List of 5,000 poorly executed but popular apps
Thunderbucket - Quick fire ideas for advertising and marketing.
IdeasAI - OpenAI-powered startup idea generator
PDFCrowd - Pdfcrowd is a Web/HTML to PDF online service. Convert HTML to PDF online in the browser or in your PHP, Python, Ruby, .NET, Java apps via the REST API.
The 25 Days of Ideas - Free resources for coming up with startup ideas
Business Model Patterns Card Deck - Transform your business strategy