Aviationstack ◆
Aviationstack is a scalable REST API for real-time flight tracking, historical flight data, airport info, and global aviation data.

formkeep (Developer Tools): FormKeep is a form backend for designers and developers, turning HTML forms into data-collecting endpoints with spam filtering and integrations. Pricing: from $4.99/mo. (data verified August 2026)
Transparency: if you buy through our links we may earn a commission, at no extra cost to you. Rankings cannot be bought. How we rate tools
FormKeep is an all-in-one form backend that lets you collect form submissions without building server-side code. It works by pointing your existing HTML form's ACTION URL to FormKeep, or by using its visual form builder. The service handles data collection, email notifications, spam filtering, and integrations with tools like Google Sheets, Slack, and Zapier—making it ideal for developers and designers who want a quick, robust form solution.
Building a form backend from scratch is time-consuming and error-prone. FormKeep eliminates that overhead by providing a secure, managed endpoint that captures submissions, filters spam, and forwards data to your favorite apps. It’s perfect for creating contact forms, lead capture forms, reservation systems, and newsletter signups—without worrying about server maintenance or data validation.
FormKeep is built for developers and designers who need a reliable form solution. It’s also great for marketing teams, small business owners, and agencies that want to collect leads or gather customer feedback quickly. It’s not aimed at non-technical users who need complex multi-step forms without any code—though the hosted form builder helps, some basic web skills are beneficial.
Use FormKeep to add a contact form to a landing page, collect order numbers in a support form, build a newsletter subscriber list, or automatically create leads in your CRM. The platform sends real-time notifications via email, Slack, or webhooks, and stores submissions for later retrieval.
Editorial score from our review methodology — not user ratings.
formkeep pricing: from $4.99/mo.
Spam protection, 50 submissions per month, form designer, branded thank-you page, daily email notifications, 1-month retention, unlimited forms.
1,000 submissions per month, dynamic field rules, no FormKeep branding in emails/forms, webhooks, file attachments, 1 form included, 3-month retention.
10,000 submissions per month, real-time notifications, all integrations (Google Sheets, Slack, etc.), autoresponders, 3 forms included, 6-month retention.
100,000 submissions per month, team members with view/update roles, phone support, permanent retention, 10 forms included.
All plans include spam filtering. Enterprise custom pricing available for unlimited submissions and advanced needs.