What are the differents excercices for better fluency and self-therapy?

What are the differents excercices for better fluency and self-therapy? I'm trying to look for a therapy or excercices for my speech, and in the process I found this app: Stamurai. Can somebody tell me if it is legit? On the other hand, what excercies did you find useful and what were they? I'm finding nothing on the Internet. Note: Right now due to school I have no time for a specialist, so I wanna try things for my self in the meantime. Sorry for possible typos.