There are two areas to see a signed contract.
From the home screen tap on the Contracts dashboard. From there, you can filter by time (W-week, M-Month, Y-Year, T-Total or All) or you can tap on Filter on the top right and select signed or unsigned.
If you're looking for a specific client, head to their profile and tap on history. There, they will have their own Contracts dashboard where you can see the ones they have signed or not signed.