AirMap mobile app [1] has a very comprehensive database of no fly zones, airports/airfields, and summaries of national rules. It works well in US/Canada and lots of countries in Europe too.

I find it often misses local city or park-level rules so I'd always use it in conjunction with a local jurisdiction's app (if available), as well as checking council websites etc.

[1]: https://play.google.com/store/apps/details?id=com.airmap.air...