The Go Paddling app is available for both iOS and Android. It features a database of over 25,000 user-curated kayaking launch points.
There are many paddling forums, groups, and associations online. A kayaking subreddit, for instance, has over 90,000 members that you can interact with and ask questions about finding the best spot to paddle.
State and national parks often list the best places to go kayaking. If there's a park near you, check it's website to see if there's any good kayaking in the park!
Many kayaking websites have interactive maps. They are often overly broad, so you’ll need to be very specific about your requirements.