Question: I'm looking for a way to integrate email and calendar services into my app without having to handle multiple complicated APIs.

If you're looking for a more comprehensive integration of email and calendar services into your app, Nylas is a good option. This unified API platform makes integration easier with APIs for email, calendar and contacts. With features like easy integration, high availability and real-time notifications, Nylas supports a range of programming languages and offers code examples. It also offers a free tier for up to 5 accounts and is designed for large-scale use, with more than 34.5 billion API transactions per day.

Another option is Zapier, which automates workflows across more than 7,000 app integrations. It doesn't offer a calendar API, but its large library of prebuilt templates and customizable workflows can be used to automate email, calendar event and other tasks. The service is geared for workflow automation and productivity, so it's good for businesses of all sizes.

If you want a more integrated email and calendar experience, BlueMail is a cross-platform app that supports multiple mail providers and integrates with calendar. It's got features like instant push notifications and unified folders, and it's got Generative Email AI (GemAI) to summarize and draft emails. It's available on multiple platforms, protects user privacy and security, and offers a range of pricing tiers depending on your needs.

Last, fwd2cal is an AI calendar assistant that creates calendar events from email threads you forward to Google Calendar. It's free and open-source, supports multiple email addresses and is designed to protect privacy since it doesn't store emails. It's a good option if you want to keep your email private while still scheduling appointments.