[AC Question]

I have a Google nexus 7 and a Samsung S5 what app can I use to sync the devices together

[B. Diddy]

Welcome to Android Central! What exactly do you mean by sync? You want the exact same apps and files on both devices? That's not necessarily possible, since they're two different devices that can have different app compatibilities. If you log into both devices using the same Google account, you can install the same apps (depending on compatibility) and access the same cloud content. You could also use an app like Helium to backup one device and see if it will restore to another, but I've never tried it myself. This won't actually sync the devices, though.