Ki Society has them they are aikido. Ki Society Internationale (split off from Ki Soc in Europe), Ki federation of Great Britain led by Ken Williams, the longest serving aikido teacher in the UK. Aikido Yuishinkai under Koretoshi Maruyama Sensei (was the heir apparent to Tohei Sensei until he resigned in the early 90s). In addition to these there are a number of other independent ki soc derived organisations based in the US I forget the names of.
Oh, I was wondering where all their Europe dojo were. KNK Internationale, that's an important one to remember.
Other lineages that trace back to Tohei that I know of include Kokikai and Seidokan, and Suenaka-Ha.
Also Shin Budo Kai (maybe?). Imaizumi sensei is a direct student of K.Tohei sensei but I don't know if he kept ki-development in his curriculum.
One day I might compile a big list of all these Ki-based aikido ryuha... and either update wikipedia with it or put it on some public website.... and save another newbie the hours of bewilderment that I had to go through grokking all these ryuha.