My Period Apps Don't Match

Does anyone else have 2-3 period tracking apps? If so, do any of your apps match in regards to when you should ovulate, and when your period should start? I have 3 (That may be a lot lol) but 2 of them have overlapping days and one is just other doing it's own thing. Normally GLOW is 1-2 days early or late....1 varies quite a bit (I think because I have had it for so long and at one point I was horrible at tracking) and the other is fairly new but it seems to be the most accurate....I think, the jury is still out on that one. HOWEVER, the app that varies and the app I have been using for years have overlapping ovulating days. Oh me, oh my, oh bother. Does anyone else have this issue?