Do you use any apps? Have you find them useful?

Do you use any apps? Have you find them useful? So I've been stuttering my whole life, and just recently I realized there could be apps to help me with my stutter. When I searched the App Store (iOS) I couldn't find anything useful under "stutter", and searching for "speech therapy" had mostly kid-oriented apps (it's not a bad thing but I'm in my mid 20's and colorful, smiley bugs are just not for me). I did google for "stutter apps" tho, and I got a couple of results, but the reviews were very mixed. So my question is, have you used any app that you recommend? Did you like it or felt that it helped you in anyway? I still don't know what to think about stutter apps. I'd like to read what others think about this!