FileMaker has built-in spell check features, which you can activate. Look under File > File Options > Spelling.
You can also use scripting to allow on-demand spell check. There are several script steps that facilitate this:
Check Found Set
Edit User Dictionary
Or is there a feature you're looking for that these don't cover?
These are not avalible in FMgo, just FMpro. Unless I am incorrecet there is no way to trigger a spell check.
Hmn. You're right. Sorry, didn't check the iOS compatibility on the script steps.
Not sure if there's another way to do it. Maybe someone else has a good idea.
Please see chapter 13 of the FTS, freely available AFAIK. The Go app uses native iOS spell check, so you are left to (and better served with, IMO) the native spelling check of your device.