The entire app is available offline so no internet connection is needs, which is good for when using a device that does not always have a data connection.
Most of the options on this page are thin interface skins over the freely available EDICT dictionary provided to the public originally by Jim Breen. (http://www.edrdg.org/jmdict/edict.html)
Kenkyuusha's, on the other hand, is a professionally curated dictionary by a major Japanese publisher.
The free version shows the 1006 Gakushū kanji. Some versions (desktop and android) give a 30 day full version trial before reverting to the limited version.
There is often a slight correlation between pronunciation and shades of meaning for kanji, which most dictionaries don't seem to show you. Jishop will try to tease these connections out, helping to significantly clarify some rather broad kanji.
Most EDICT skins use the radkfile mechanism, which is 1) riddled with errors and 2) rather incomplete. Jishop has its own non-bushu lookup mechanism that is significantly easier to use once you get used to the slightly quirky interface.