Is glow <a href="https://play.google.com/store/apps/details?id=com.glow.android">fertility tracker</a> more accurate then <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a>?

Glow <a href="https://play.google.com/store/apps/details?id=com.glow.android">fertility tracker</a> says I’m going to start my period in 7 days and <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> is saying I’m going to start my period in 8 days. Not sure which one to believe. I’m pretty sure both the apps are made through glow. And when I set up my cycle days and which days I started my period I put them the same in both apps. So I’m not sure which one is actually right?