We use mostly geocheck.org which is very versatile with child waypoints and inexact solutions, and certitudes.org which supports keyword solutions.
The only checker we must recommend AGAINST, is geopuzzler.ml
* it requires registration
* the people behind the checker are anonymous and do not respond to email
* we received a warning from another cacher, who has strong evidence geopuzzler.ml was involved in breaking into his geocaching.com account, accessing his corrected coordinates (and maybe more)
* the few caches it is being used on (all published by the same geocaching.com account), are currently all disabled by the reviewer, because of this situation
