I have been a SwiftKey user for some years now primarily because the keyboard supports multiple languages (namely, Japanse, English and German).
Unfortuntately, my satisfcation with Japanese language feature has deteriorated considerably over the last year or so due to its very poor level of Japanese prediction. Below are examples of such poor predictions:
Typing "とうじょうけん" brings up "登場kenn、登場けん、とう条件、頭条件、トウジョウケン、とうじょうけん、ﾄｳｼﾞｮｳｹﾝ", etc. as the candidates. As any Japanese user knows, there are no such words as "登場kenn、登場けん、とう条件、頭条件" and the correct candidate would be "搭乗券".
Typing "いえのきど” brings up "家のキド、I えのきdo、家のきど、家の木戸", etc. where the fourth candidate "家の木戸" is the most likely candiate. Maybe those learning beginner Japanese might use either the first or the third candiate, but the second candidate "I えのきdo" is not even a Japanese word.
Typing "とうさんのきき" brings up "父さんの危機、父さんの聞き、父さんの聴き、父さんのきき、トウサンノキキ", etc. as the candidates. ”父さんの危機” is a good candiate but another likely cadidate would be "倒産の危機".
Typing "ふどうさんばいばい" brings up "不動産(・ω・)ノ、hudousannbaibai、不動、浮動、フドウサンバイバイ、ふどうさんばいばい", etc. as the candidates. OK, maybe some people use "不動産(・ω・)ノ、hudousannbaibai" but the most probable cadidate would be "不動産売買".
While I have been such a great admirer of SwiftKey and cannot express enough how grateful I have been to the software (not only mentioning that is is free of charge!!), I am also hugely disappointed by the fact SwiftKey has not made any improvement on Japanese prediction feature.
I would like keep using the keyboard for as long as I can foresee in the future, but I am honestly not sure how long I can bear with the lack of qualitiy prediction. It would be great if the production team can look into this problem seriouly then you wont lose at least one Japanese customer :)