What's the best keyboard for Devanagari script? Or specifically for Nepali?
This is the place to review and discuss the advantages and shortcomings of the various keyboards for use with Indic languages.
We won't list InKey keyboards here, as no further development is happening with InKey, but if you're waiting on a Keyman keyboard to be developed for an Indic script not listed here, check out the options available at inkeysoftware.com. -Just don't expect to get support from the developer.
Note that additional Keyman keyboards under development by NLCI but not yet released on the Keyman site (Odia, Gujarati, Telugu, Gurumukhi) can be found at github.com/nlci.